Slave state legislators had more power and what part of congress during the 1850s

The answer is:

In both the House of Representatives and the Senate is where Slave State Legislators had more power during the 1850s.

Explanation:

African Americans primarily favored the Republican Party in the 1850's due to its more tangible efforts in achieving the abolition of slavery. The South had long favored the state's right to legal slavery and was also a Democratic stronghold.

In The Senate, it wasn't until the Compromise of 1850 that California was admitted as a free state, however California agreed to send one pro-slavery and one anti-slavery senator to Congress in order to avoid creating a free state majority in the Senate and keep things even.

Slave State legislatures had more power in THE SENATE during the 1850s.