It would be the "legislative branch" that is divided into two separate chambers--one is called the Senate and the other is called the House of Representatives. This is called a "bicameral" legislature.
Original--President by electoral college, Senators by state legislators, and House of Representatives by direct vote. Direct vote is by land-owning, white, males who were 21 or older.
President has remained the same.
Senators--changed to direct vote with the 17th Amendment in 1912
House of Representatives has remained the same.
Those who can vote has changed through time. In the 1820s and 1830s states removed the landowner condition for voting. In 1870, black men were given the right to vote under the 15th Amendment. In 1920, women were granted the right to vote under the 19th Amendment. Lastly, the age was moved from 21 to 18 in 1971 with the 26th Amendment.
Black identity and cultures