• January –
Klamath and Salmon River War: In
Klamath County, California, hostility between settlers and the local Native Americans becomes violent. The
California State Militia and U.S. Army intervene, ending the war in March. • January 23 – The first bridge over the
Mississippi River opens in what is now
Minneapolis, Minnesota (a crossing made today by the
Hennepin Avenue Bridge). • January 26 – The
Point No Point Treaty is signed in the
Washington Territory. • February 12 –
Michigan State University (the "pioneer" land-grant college) is established. • February 15 – The
North Carolina General Assembly incorporates the
Western North Carolina Railroad to build a rail line from
Salisbury to the western part of the state. • February 22 –
Pennsylvania State University is founded as the Farmers' High School of Pennsylvania. • March 3 – The
U.S. Congress appropriates $30,000 to create the
U.S. Camel Corps. • March 16 –
Bates College is founded by abolitionists in
Lewiston, Maine. • March 30 – Elections are held for the first
Kansas Territory legislature. Missourian '
Border Ruffians' cross the border in large numbers to elect a pro-
slavery body. • April –
Cincinnati riots of 1855: Tension between
nativists and German-American immigrants in
Cincinnati breaks out into territorial street fighting on election day. • May 17 – The
Mount Sinai Hospital is dedicated (as the
Jews' Hospital) in
New York City; it opens to patients on June 5. • June 6 –
Portland Rum Riot: A crowd gathers at a storehouse believed to hold alcohol in
Portland, Maine. The militia is called in and fires on the crowd to disperse the crowd, killing one person. • June 28 – The
Sigma Chi fraternity is founded at
Miami University in Oxford, Ohio. • July 1 –
Quinault Treaty signed,
Quinault and
Quileute cede their land to the United States. • July 2 – The
Kansas Territorial Legislature convenes in
Pawnee and begins passing
proslavery laws. • July 4 –
Walt Whitman's poetry collection
Leaves of Grass is published in
Brooklyn. • July 4 –
Amelia Bloomer speaks in favor of
women's rights and suffrage in
Omaha,
Nebraska. • July 6 – The Kansas Territorial Legislature meets for the last time in Pawnee, voting to relocate to
Shawnee, closer to the border of
slave state Missouri. • July 16 – U.S. Indian commissioner
Isaac Stevens signs the
Hellgate treaty with Native Americans living in modern-day western
Montana. • August 6 –
Bloody Monday: Protestant mobs attack
Irish and
German Catholics on an election day in
Louisville, Kentucky, causing 22 deaths. • September 3 –
First Sioux War:
Battle of Ash Hollow – U.S. forces defeat a band of
Brulé Lakota in present-day
Garden County, Nebraska. • October 5 –
Yakima War:
Battle of Toppenish Creek – In the
Yakima River Valley, a band of
Yakama warriors forces a company of U.S. soldiers to retreat in the first battle of the War. • October 28–31 –
1855 Fiji expedition: The U.S. Navy dispatches the
USS John Adams to
Viti Levu, Fiji, to protect American interests. One American sailor is killed and two Marines are wounded. • November 1 – 31 people are killed in the
Gasconade Bridge train disaster in
Missouri. • November 9–10 –
Yakima War:
Battle of Union Gap – American soldiers attack a
Yakama village, forcing the village to retreat. • November 21 – Large-scale
Bleeding Kansas violence begins with events leading to the
Wakarusa War between antislavery and proslavery forces.
Ongoing •
Samuel Colt incorporates his business as the
Colt's Patent Firearms Manufacturing Company and opens a new factory, the
Colt Armory, in
Hartford, Connecticut.
Horace Smith and
Daniel B. Wesson form the
Volcanic Repeating Arms Company in New England. •
California Gold Rush (1848–1855) •
Bleeding Kansas (1854–1860) •
Third Seminole War (1855–1858) •
Yakima War (1855–1858) ==Births==