What new free states entered the union between 1820 and 1854?

In 1820 an agreement called the Missouri Compromise was reached. The compromise allowed Missouri to come into the Union as a slave state and Maine would be a free state. Congress drew an imaginary line across the middle of the United States running from the east coast to the Pacific Ocean.

Explanation:

it was on the rise and doing very well and would continue to do well until the great depression from 1929-1939