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, facing re-election in 1850; Class 2 meant their term began in the last Congress, facing re-election in 1852; and Class 3 meant their term began in this Congress, facing re-election in 1854.
