Why did the house of representatives pass the tallmadge amendment in 1819? the amendment had already passed in the senate. the amendment was backed by the north and the south. the north controlled the house of representatives. the south controlled the house of representatives.

The answer is The amendment had already passed in the Senate
Back then, it is customary for all legislative to be backed by both houses in the Congress.
The Tallmadge amendment was submitted by James Tallmadge, Jr that requested the state of Missouri to be admitted into a union as a free state.