His father had established a workshop in
Philadelphia, Pennsylvania by the time Solomon was 19, and another in
Baltimore, Maryland by 1849, where both became interested in portrait photography using the
daguerreotype method. They also had offices of some type in Charleston, South Carolina and in New York City. A portrait Solomon painted at age 25, "Child with Rabbits" would later be incorporated into
national bank notes of several U.S. state banks. In 1853, Colonel
John C. Frémont, who had made several trips exploring the west and had unsuccessfully tried to make daguerreotypes to document his group's journeys, invited the young artist to accompany him as he attempted to prove that a “central route” near the thirty-eighth parallel would be the best path for a planned transcontinental railroad. Accepting the challenge, Carvalho traveled from New York to St. Louis by rail, and then took a steamboat up the
Missouri River to
Westport in
Missouri. During the trip, despite the frigid weather which made chemical combinations difficult, Carvalho made near daily portraits of expedition members, the Native Americans they met, and the landscape. A major part of his near 300 daguerreotypes taken during the expedition were lost in a fire. The surviving ones would later be given by Fremont to
Mathew Brady to copy on wet plate negatives, and they became mixed up with others of Brady's work. Carvalho published his diary of the five-month journey, ''Incidents of Travel and Adventure in the Far West; with Colonel Fremont's Last Expedition (1860),'' possibly before Frémont's presidential campaign or to fulfill a promise made to Mormon leaders during his recuperation. After the
American Civil War, Carvalho moved his family to New York City, but cataracts impaired his continuing portrait work by 1869, and would ultimately blind him. He became an inventor, and two patents he received for steam superheating in 1877 and 1878 would not only win the Medal of Excellence from the American Institute of New York, but achieve financial security for the family. He and Sarah remained active in New York's Jewish community, and he tried to harmonize modern scientific thought and the biblical story of creation found in the
book of Genesis in his final years, although that work was never published. ==Death and legacy==