Events January–March January 29 – Henry Clay introduces the Compromise of 1850 to the United States Congress. January 31 – The University of Rochester is founded in Rochester, New York. January – Sacramento floods. February 28 – The University of Utah opens in Salt Lake City. March 5 – The Britannia Bridge opens over the Menai Strait in Wales. March 7 – United States Senator Daniel Webster gives his "Seventh of March" speech, in which he endorses the Compromise of 1850, in order to prevent a possible civil war. March 16 – Nathaniel Hawthorne's historical novel The Scarlet Letter is published in Boston, Massachusetts. March 19 – American Express is founded by Henry Wells and William Fargo. March 31 – The paddle steamer , bound from Cork to London, sinks in the English Channel. January–June April 4 – Los Angeles is incorporated as a city in California. April 15 San Francisco is incorporated as a city in California. Angers Bridge collapses in France killing around 226 of the soldiers crossing it at the time. April 19 – The Clayton–Bulwer Treaty is signed by the United States and Great Britain, allowing both countries to share Nicaragua, and not claim complete control over the proposed Nicaragua Canal. April Pope Pius IX returns from exile to Rome. Stephen Foster's parlor ballad "Ah! May the Red Rose Live Alway" is published in the United States. May 23 – The puts to sea from New York to search for Franklin's lost expedition in the Arctic. May 25 – The hippopotamus Obaysch arrives at London Zoo from Egypt, the first seen in Europe since Roman times. June 1 The transportation of British convicts to Western Australia begins, as the transportation of British convicts to other parts of Australia is phased out, when the ship Scindian arrives in Fremantle, with 75 male prisoners. The postage stamp issues of Austria begin with a series of imperforate typographed stamps, featuring the coat of arms. The 1850 United States Census shows that 11.2% of the population classed as "Negro" are of mixed race. June 3 – Kansas City, Missouri, is incorporated by Jackson County, Missouri, as the Town of Kansas (traditional date of its founding). July–September July – Taiping Rebellion: Hong Xiuquan orders the general mobilisation of rebel forces in China. July 1 – St. Mary's School for Boys (the future University of Dayton) opens its doors in Dayton, Ohio.