Early colonial period in
Compton, Maryland, the oldest Catholic church in continuous operation from the
Thirteen Colonies in
St. Louis Catholicism first entered the territories that would become the United States through
Spanish colonization. Spanish expeditions brought
Catholic clergy to the present-day
Virgin Islands in 1493,
Puerto Rico in 1508, Florida in 1513, and later to regions of the
Southeast and the
Southwest. The earliest documented Catholic Mass within what is now the United States was celebrated in 1526 by
Dominican friars
Antonio de Montesinos and Anthony de Cervantes for the short-lived
San Miguel de Gualdape colony. Spanish missions, including those established in
Alta California beginning in 1769, left a lasting religious and cultural legacy. Until the 19th century, missionary activity in these regions operated under Spanish—and, in some areas,
Portuguese—colonial authority. In the
British colonies, Maryland was founded in the 17th century as a
proprietary colony with a notable
English Catholic presence, contrasting with the predominantly Protestant colonies of Massachusetts and Virginia. Pennsylvania, granted to
William Penn by King
James II, adopted a policy of religious toleration that attracted settlers of various Christian traditions, including Catholics. Catholics were also present in the
Province of New York, named after James II, the last Catholic monarch of England. By 1785, the estimated Catholic population in the United States was approximately 25,000, concentrated mainly in Maryland (15,800), Pennsylvania (7,000), and New York (1,500), served by only 25 priests—less than 2% of the total population of the Thirteen Colonies. Following the
Declaration of independence in 1776 and the American victory in the
Revolutionary War, the new United States incorporated territories with longstanding Catholic histories under the former colonial administrations of
New France and
New Spain. Maryland, founded in 1632 under the proprietorship of
Lord Baltimore, was established as a colony intended to accommodate English Catholics. Its early policy of religious toleration, however, was repeatedly disrupted. In 1650, Puritan settlers in Maryland repealed the colony's Act of Toleration, outlawed Catholicism, and expelled Catholic clergy. The act was reinstated in 1658, but another rebellion in 1689 again ended toleration, and the colonial assembly—dominated by Anglicans—established the
Church of England and barred Catholics and
Quakers from holding public office. In contrast, New York under Governor Thomas Dongan, a Catholic, maintained comparatively broader religious tolerance. Widespread legal restrictions on Catholics in the colonies began to diminish only with the American Revolution. By the mid-18th century, Catholics remained a smaller minority. A Catholic Maryland official in 1756 estimated approximately 7,000 practicing Catholics in Maryland and 3,000 in Pennsylvania. The Colonial Williamsburg Foundation estimates that by 1765 Maryland had about 20,000 Catholics and Pennsylvania about 6,000, within total colonial populations of roughly 180,000 and 200,000 respectively. At the start of the American Revolution in 1776, Catholics represented about 1.6% of the population—around 40,000 people in the Thirteen Colonies—with only about 25 priests serving them. Another estimate places the Catholic population at 35,000 in 1789, with roughly 60% residing in Maryland and only about 30 priests nationwide. In 1785, John Carroll, later the first Catholic bishop in the United States, reported 24,000 registered communicants, 90% of whom lived in Maryland and Pennsylvania. After independence, the
Holy See reorganized Catholic governance in the United States, establishing a new
ecclesiastical structure under American leadership. Catholics served in the Continental Army, and the new nation maintained close ties with Catholic France, whose military and financial support was crucial to the American victory. George Washington emphasized religious toleration, prohibiting anti‑Catholic celebrations such as "
Pope’s Day" in 1775 and attending services of various Christian denominations, including Catholic liturgies. Several European Catholics played significant military roles in the Revolution, including the
Marquis de Lafayette, the
Comte de Rochambeau, the
Comte d’Estaing,
Casimir Pulaski, and
Tadeusz Kościuszko. Irish‑born Commodore
John Barry, often credited as a founder of the U.S. Navy, also contributed prominently. Washington later acknowledged the contributions of Catholic leaders and France's support in a letter to
John Carroll. Beginning around 1780, disputes arose between
lay trustees and clergy over control of church property, a conflict that diminished after the
Plenary Councils of Baltimore in 1852 affirmed episcopal authority. Historian Jay Dolan notes that the Revolution transformed the status of Catholics, who had previously faced political, professional, and social discrimination; new state constitutions and the federal Constitution prohibited religious tests and expanded civil rights. Washington's public support for religious liberty reinforced these developments, and states gradually repealed remaining colonial‑era restrictions on Catholics. Catholics also participated in the framing of the new republic.
Daniel Carroll and
Thomas Fitzsimons served as delegates to the
Constitutional Convention in 1787. John Carroll was appointed Prefect Apostolic by the Vatican, oversaw the early organization of the American Catholic Church, developed plans for
Georgetown University, and became the first bishop in the United States in 1789.
19th century of the
St. Patrick's Cathedral in New York City, completed in 1878 Catholicism spread throughout America with the territorial gains from the French and Spanish Empires, including the annexation of Mexican lands. The
Louisiana Purchase in 1803 transformed the vast territories of
French Louisiana into American states. The colony's descendants, today known as the
Louisiana Creole and
Cajun people, came from a culturally Catholic and French population. During the 19th century, previously Spanish territories became territories of the United States, starting with Florida in the 1820s, then parts of Mexico on the border, and the annexation of Mexico after the
Mexican–American War; this land acquisition, known as the
Mexican Cession, caused the new states of California,
Nevada,
Utah, most of
Arizona,
New Mexico,
Colorado, and
Wyoming to form. Both French and the Spanish also named numerous settlements after Catholic saints. Following the
Spanish-American War in 1898, the United States took control of
Puerto Rico,
Guam, the
Philippines, and
Cuba for a time, which all held Spanish Catholic colonial history. However, they were not made into states. During an immigration surge starting in the 1840s, Catholic German, Irish, and European immigrants arrived in large numbers, and after 1890, Italians and
Poles formed the largest Catholic group. Many European countries contributed to this wave of Catholic immigration, including
Quebec. Catholics had become the country's biggest denomination by 1850. Between 1860 and 1890, the population tripled to seven million.
Catholic revival and anti-Catholic movements in Chicago
Cathedral Basilica of St. Augustine in
St. Augustine, Florida Historian
John McGreevy identifies a 19th-century Catholic revival in the United States shaped by
Ultramontanism, a movement emphasizing strong loyalty to Rome, increased episcopal authority, and renewed devotional practices. This revival developed within urban parishes, schools, and lay associations, and it encouraged more frequent participation in the sacraments, deference to bishops and the pope, and pastoral discouragement of intermarriage with Protestants. Leadership within the American hierarchy increasingly reflected the influence of Irish-born clergy, who generally aligned with broader Ultramontane trends. American bishops, many of them Irish, tended to support the international Ultramontane movement that culminated in the First Vatican Council's definition of
papal infallibility in 1870, though the council's outcome was shaped primarily by European theological and political dynamics. The
Plenary Councils of Baltimore in 1852, 1866, and 1884 standardized discipline within the American Church and played a central role in shaping national Catholic life. The Third Plenary Council commissioned the
Baltimore Catechism and endorsed the establishment of the
Catholic University of America, which was chartered in 1887.
Jesuits—including some who had previously faced suppression in Europe—founded or strengthened several American secondary schools and universities, and other religious communities such as the
Dominicans, the
Congregation of Holy Cross, and the
Franciscans also established major educational institutions. In the 1890s, Vatican officials expressed concern that certain interpretations of Catholic thought in the United States reflected excessive liberalism, leading to what became known as the
Americanism controversy. French cleric Charles Maignen criticized the ideas of
Isaac Hecker, founder of the
Paulist Fathers, accusing him of subjectivism and tendencies resembling Protestant
individualism. Although the Vatican's concerns were directed at interpretations of Hecker's ideas rather than at Hecker himself, some of his supporters were labeled as proponents of "Americanism," a term later rejected by the American hierarchy. Throughout American history,
anti-Catholic movements have appeared: the 1850s
American nativist political party
Know Nothing, the 1890s anti-Catholic secret society
American Protective Association, and the 1920s American white supremacist hate group
Ku Klux Klan. Animosity from some Protestants waned as Catholics demonstrated their patriotism in
World War I, commitment to charity, and dedication to democratic values.
Nuns and sisters (1834–1921), key in establishing
Catholic University in 1887, advanced labor rights and Catholicism's harmony with American civic values. Throughout American religion and education,
nuns and
sisters have played a major role since the early 19th century in fields such as education, nursing, and social work. In Catholic Europe, convents were endowed and sponsored by the aristocracy, but very few rich American Catholics existed and no aristocrats. Thus, entrepreneurial women founded religious orders that were staffed by devout women from poor families. The numbers grew rapidly: 900 sisters in 15 communities in 1840, 50,000 sisters in 170 congregations in 1900, and 135,000 sisters in 300 different congregations by 1930. Beginning in 1820, sisters outnumbered the priests and brothers. In 1965, the membership peaked at around 180,000 members, falling to 56,000 in 2010, as many women left the orders and not enough joined.
The Congregation for the Doctrine of the Faith initiated a doctrinal assessment of the
Leadership Conference of Women Religious in 2008, expressing concern about certain theological positions. Contemporary reporting noted that some U.S. Catholics viewed the investigation critically. The assessment concluded in 2015, when Pope Francis closed the inquiry.
20th–21st centuries launched the television program
Life Is Worth Living in the 1950s, using the emerging medium of
mass communication to present Catholic teaching to a national audience and becoming one of the era's most prominent religious broadcasters. During the major immigration waves from the 1840s to 1914, Catholic bishops frequently established separate parishes for distinct ethnic communities, including Irish, German, Polish, French Canadian, and Italian immigrants. In
Iowa, for example, the development of the
Archdiocese of Dubuque under Bishop
Mathias Loras, including the construction of
St. Raphael's Cathedral, reflected efforts to meet the pastoral needs of Irish and German Catholics. Italian Jesuits also contributed significantly to Catholic expansion in the American West. Between 1848 and 1919, approximately 400 Jesuit expatriates founded or staffed numerous institutions, including colleges in San Francisco, Santa Clara, Denver, Seattle, and Spokane. They also ministered to miners in Colorado, to Native American communities in several states, and to Hispanic Catholics in New Mexico, where they established churches, published religious materials, and operated schools. By the early 20th century, roughly one‑sixth of the U.S. population was Catholic. More recent immigration from the Philippines, Poland, Mexico, and other parts of Latin America has further diversified American Catholicism. This multiculturalism is reflected in widespread multilingual liturgies, including Masses offered in Spanish,
Tagalog,
Polish,
Vietnamese, and other languages, as well as the continued use of Latin in some parishes. In 1908, the United States, along with Canada and five Western European countries, were removed from the
Propaganda Fide's jurisdiction and placed under a separate hierarchy. Sociologist Andrew Greeley, a Catholic priest and scholar at the
University of Chicago, conducted extensive national surveys of American Catholics in the late 20th century. His work emphasized the enduring importance of ethnic identity in American Catholic life and described what he called the "Catholic imagination," characterized by a sacramental worldwide and a strong attachment to ritual, narrative, and symbolism. Greeley argued that these cultural elements helped sustain Catholic identity even when individuals disagreed with aspects of church teaching. He also maintained that the 1968 encyclical
Humanae vitae, which reaffirmed the Church's prohibition of
artificial contraception, contributed to a marked decline in weekly Mass attendance between 1968 and 1975. In 1965, approximatively 71% of American Catholics attended Mass regularly (at least weekly). In the late 20th century, the Catholic Church in the United States received
scrutiny and controversy due to heightened allegations of
clerical sexual abuse, especially involving children and
adolescents; some observers pointed toward episcopal negligence in arresting and charging clergy for these crimes, which led to numerous civil suits, costing Catholic dioceses hundreds of millions in damages. To safeguard parishioners and the Church from further abuses and scandals, policies and diocesan investigations into seminaries have been enacted to try to correct these former abuses of power; one initiative includes the
National Leadership Roundtable on Church Management, a group of laymen dedicated towards bringing better administrative practices to dioceses. According to a 2015
Pew Research Center study, 39% of American Catholics reported attending Mass at least once a week, while 40% attended once or twice a month. Although trusteeism was largely resolved in the 19th century, occasional disputes over parish property have continued. Examples include the interdict issued in 2005 to the board of
St. Stanislaus Kostka Church in
St. Louis and debates in
Connecticut in 2006 over
proposed legislation concerning parish financial governance. Questions about
parish assets have also arisen when dioceses have closed or consolidated parishes. In 2009, English journalist
John Micklethwait described American Catholicism as having adopted well to the nation's pluralistic environment while maintaining its core characteristics. In 2011, an estimated 26 million Americans who had been raised Catholic no longer identified with the Church. A 2014 Pew study found that 31.7% of American adults were raised Catholic, but 41% of that group no longer identified as Catholic. A 2015 study by
Georgetown University's Center for Applied Research in the Apostolate estimated that 81.6 million Americans—about 25% of the population—self‑identified as Catholic, including those not affiliated with a parish. Approximately 68.1 million, or 20% of the population, were registered parishioners. About 25% of Catholics reported attending Mass weekly, and 38% attended at least monthly. The study also found that the Catholic Church in the United States is one of the nation's most racially and ethnically diverse religious bodies, with
Hispanics comprising 38% of Catholics and
Black and
Asian Catholics each representing about 3%. Scholars have noted that this diversity has encouraged efforts to build a more inclusive ecclesial identity, echoing the aspirations of 19th‑century leaders such as Archbishops John Ireland and James Gibbons, who sought to integrate Catholic immigrants fully into American society. Contemporary surveys show that only about 2% of American Catholics receive the sacrament of reconciliation regularly, while most go once a year or less. Catholic teaching requires confession at least annually and after committing mortal sin before receiving Holy Communion. In late 2019,
Matthew Bunson argued that Catholicism has declined due to
secularism, materialism, and
relativism, which have opened gaps in
catechesis, practices, and beliefs. Since 1970, weekly Church attendance has fallen from 55% to 20%, priests from 59,000 to 35,000, and people leaving Catholicism increased from under 2 million to over 30 million today. In 2022, 42,000 nuns were left in the United States, a decline of 76% over 50 years, with fewer than 1% of nuns being under the age of 40. According to the Pew Research Center, 36% of all Catholic adults in the United States are Hispanic in 2025, up from 27% in 2009. They are more likely to wear or carry religious items, practice devotions to the Virgin Mary or saints, pray the rosary, and light candles for spiritual or religious reasons. In the
2024 presidential election, they voted 55% for
Kamala Harris, while they voted 66% for
Joe Biden in
2020, a large shift. In August 2023 poll, Hispanic Catholics leaned 60-35 in support of
Democrats, while white Catholics leaned 61-37 for
Republicans. In 2022, six of the nine U.S. Supreme Court justices were Catholic, showing a growing influence of Catholic policy on Supreme Court cases. Nearly two-thirds of Catholics had undermined trust in the Church's leadership due to the clergy sexual abuse crisis; however, 86% of Catholics still considered religion an important aspect of their lives. Following
Pope Francis's death in 2025, the
conclave elected Cardinal
Robert Francis Prevost as the first pope from the United States. Prevost was born in Chicago, was an
Augustinian, and attended
Villanova University. He chose the
papal name of Leo XIV. ==Organization, personnel, and institutions==