District of Columbia is about 743 times smaller than Alabama.

Alabama is approximately 131,426 sq km, while District of Columbia is approximately 177 sq km, making District of Columbia 0.13% the size of Alabama. Meanwhile, the population of Alabama is ~4.8 million people (4.2 million fewer people live in District of Columbia).
Tip: This to-scale comparison of Alabama vs. District of Columbia uses the Mercator projection, which distorts the size of regions near the poles.