District of Columbia is about 1.2 times bigger than Wallis and Futuna.

Wallis and Futuna is approximately 142 sq km, while District of Columbia is approximately 177 sq km, making District of Columbia 25% larger than Wallis and Futuna. Meanwhile, the population of Wallis and Futuna is ~15,891 people (585,832 more people live in District of Columbia).
Tip: This to-scale comparison of Wallis and Futuna vs. District of Columbia uses the Mercator projection, which distorts the size of regions near the poles.