The Thirty-Third Congress of the United States convened from December 4, 1853, to March 3, 1855. It was marked by significant debates over issues such as slavery and territorial expansion, particularly in relation to the newly acquired lands from the Mexican-American War. The Congress was composed of the House of Representatives and the Senate, with a total of 234 members in the House and 62 in the Senate. During this Congress, notable legislation included the Gadsden Purchase, which aimed to facilitate a southern transcontinental railroad. The political landscape was dominated by the tensions between the Democratic Party and the Whig Party, as well as the emergence of the Republican Party in response to the growing sectional conflicts.