The apportionment of seats in the House of Representatives was based on the 1850 United States census.
During this congress, two Senate seats were added for each of the new states of Minnesota and Oregon.
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.
The names of members of the House of Representatives are preceded by their district numbers.
House seats by party holding plurality in state | |
---|---|
80.1-100% Democratic
|
80.1-100% Republican
|
60.1-80% Democratic
|
60.1-80% Republican
|
Up to 60% Democratic
|
Up to 60% Republican
|