1820-1970 Missouri Gateway To The West Sesquicentennial Medal-Any Info?

It cannot be a sesquicentennial for statehood considering that Missouri did not become a state until 1821. It fits with the Missouri Compromise of 1820 but it seems quite odd to commemorate the legislation that allowed slavery in Missouri

The 1970 medal commemorates the passage of the Act of Admission for Missouri by the US Congress; the Act formally put the Missouri Territory on the road to statehood. It authorized the Missouri Territory to form a state government and draft a state constitution in preparation for admittance to the Union. The people of Missouri achieved both objectives in a timely manner and expected statehood to be approved in 1820 (alongside Maine).

When the US Congress reviewed Missouri's proposed constitution, however, it objected to a provision in it that would have prevented freed slaves from settling in Missouri. It took months of debate before Missouri agreed to remove the problematic provision and provided Congress with an acceptable version of its constitution. Once done, the road to statehood proceeded and Missouri was admitted in 1821.

As 1820 and 1821 each figured significantly in Missouri's road to statehood, two different series of commemorative medals were produced/sold.

Thank you Commems for shedding some light on this. That is a very good explanation.

Thank you all for responding to my question!