November 17, 1856: On the Sonoita River in present-day southern Arizona, the United States Army established Fort Buchanan to help control new land acquired in the Gadsden Purchase. January 9, 1857: The 7.9 Mw Fort Tejon earthquake affects Central and Southern California with a maximum Mercalli intensity of IX (Violent). Major legislation August 18, 1856: Guano Islands Act, ch. 164, Treaties January 26, 1855: Point No Point Treaty signed in the Washington Territory. (Ratified March 8, 1859. Proclaimed April 29, 1859) July 1, 1855: Quinault Treaty signed, Quinault and Quileute ceded their land to the United States. (Ratified March 8, 1859. Proclaimed April 11, 1859) Party summary The count below identifies party affiliations at the beginning of this Congress. Changes resulting from subsequent replacements are shown below in the "Changes in membership" section. During the elections for this Congress, opponents to the Democrats used the Whig party label inconsistently and not at all in some states. Hence in this Congress, and in accordance with the practice of the Senate and House, representatives not associated with the Democratic Party or the American Party are labeled as "Opposition." This is the first example in U.S. history of a form of coalition government in either house of Congress. Senate House of Representatives The parties that opposed the Democrats joined a coalition and formed the majority. The Know Nothings caucused with the Opposition coalition. Leadership Senate President: Vacant President pro tempore: Jesse D. Bright (D), until June 9, 1856 Charles E. Stuart (D, June 9, 1856 – June 10, 1856 Jesse D. Bright (D), June 11, 1856 – January 6, 1857 James M. Mason (D), from January 6, 1857 House of Representatives Speaker: Nathaniel P. Banks (A), elected February 2, 1856, on the 133rd ballot Democratic Caucus Chairman: George Washington Jones Members This list is arranged by chamber, then by state. Senators are listed in order of seniority, and representatives are listed by district. Senate Senators were elected by the state legislatures every two years, with one-third beginning new six-year terms with each Congress. Preceding the names in the list below are Senate class numbers, which indicate the cycle of their election. In this Congress, Class 1 meant their term ended with this Congress, requiring reelection in 1856; Class 2 meant their term began in the last Congress, requiring reelection in 1858; and Class 3 meant their term began in this Congress, requiring reelection