We need a full year to answer other than 181.
15 slave states and 19 free states during the American Civil War
4
4 million
15 free states
15
15 slave states and 19 free states during the American Civil War
4
In America there was 11 free states and 11 slave states, before the compromise.
4 million
15 free states
to many slave states being added into the union
Two states were allowed into the Union, Missouri as a slave state and Maine as a free state. http://www.loc.gov/rr/program/bib/ourdocs/Missouri.html
There were 12 slave states after the Missouri Compromise.
15
If its the end of slavery then all of the states were free
18 states were free states, 15 states were slave states 33 states overall
That would be 4 Between 1820 and 1850, eight states were added to the Union: Maine (1820), Missouri (1821), Arkansas (1836), Michigan (1837), Florida (1845), Texas (1845), Iowa (1846), and Wisconsin (1848). Maine, Michigan, Iowa, and Wisconsin were free states, while Missouri, Arkansas, Florida, and Texas were slave states. This maintained the balance between free and slave states.