Missouri is about 1,008 times bigger than District of Columbia.

District of Columbia is approximately 177 sq km, while Missouri is approximately 178,414 sq km, making Missouri 100,699% larger than District of Columbia. Meanwhile, the population of District of Columbia is ~601,723 people (5.4 million more people live in Missouri).
Tip: This to-scale comparison of District of Columbia vs. Missouri uses the Mercator projection, which distorts the size of regions near the poles.