Largest Us Cities By Population 2024. Phoenix, az (516.7 mi²) the largest city in the united states by area is sitka, alaska.sitka spans over 2,870.3 mi² (7,434.04 km²) but has a population of about only. Between 2020 and 2023, nine of the top 10 fastest growing u.s.

One city’s decline is another city’s population boom. Since 1790, when the first u.s.