700,000 people live in D.C. They have no representative in Congress.

[Wiz Imp]

9. States with populations under 1 million (+ DC)

 South Dakota 924,669
 North Dakota 796,568
 Alaska 740,133
 District of Columbia 702,250
 Vermont 648,493
 Wyoming 587,618

Additional states with lower populations than Puerto Rico

 Puerto Rico 3,203,295
 Arkansas 3,088,354
 Kansas 2,970,606
 Mississippi 2,943,045
 New Mexico 2,130,256
 Nebraska 2,005,465
 Idaho 2,001,619
 West Virginia 1,769,979
 Hawaii 1,446,146
 New Hampshire 1,409,032
 Maine 1,405,012
 Montana 1,137,233
 Rhode Island 1,112,308
 Delaware 1,051,917

Wyoming, Vermont, Alaska, North Dakota, South Dakota & Delaware all have 1 Representative
Rhode Island, Montana, Maine, New Hampshire, West Virginia, Hawaii & Idaho have 2 Reps
Nebraska & New Mexico have 3 Reps
Arkansas, Kansas, Mississippi, Iowa, Nevada & Utah have 4 Reps.