| Allendale | 6,766 | Allendale | South Carolina | Savannah-Augusta, GA | View → |
| Alpena | 28,000 | Alpena | Michigan | Traverse City, MI | View → |
| Alpine | 1,100 | Markleeville | California | Las Vegas-Reno, NV | View → |
| Amador | 41,000 | Jackson | California | Sacramento, CA | View → |
| Amelia | 13,000 | Amelia Court House | Virginia | Richmond, VA | View → |
| Amherst | 31,000 | Amherst | Virginia | Roanoke-Harrisonburg, VA | View → |
| Amite | 12,000 | Liberty | Mississippi | New Orleans-Baton Rouge, LA | View → |
| Anderson | 58,500 | Palestine | Texas | Dallas-Fort Worth, TX | View → |
| Anderson | 214,208 | Anderson | South Carolina | Greenville, SC-Asheville, NC | View → |
| Anderson | 8,000 | Garnett | Kansas | Kansas City, MO | View → |
| Anderson | 50,000 | Oak Ridge | Tennessee | Knoxville-Chattanooga, TN | View → |
| Anderson | 23,000 | Lawrenceburg | Kentucky | Lexington-Bowling Green, KY | View → |
| Andrew | 17,500 | Savannah | Missouri | Kansas City, MO | View → |
| Andrews | 19,500 | Andrews | Texas | El Paso-Odessa, TX | View → |
| Androscoggin | 109,000 | Lewiston | Maine | Portland-Bangor, ME | View → |
| Angelina | 86,900 | Lufkin | Texas | Houston, TX | View → |
| Anne Arundel | 600,000 | Annapolis | Maryland | Baltimore, MD | View → |
| Anoka | 370,000 | Blaine | Minnesota | Minneapolis-St. Paul, MN | View → |
| Anson | 23,000 | Wadesboro | North Carolina | Charlotte-Greensboro, NC | View → |
| Antelope | 6,300 | Neligh | Nebraska | Lincoln, NE | View → |
| Antrim | 24,000 | Bellaire | Michigan | Traverse City, MI | View → |
| Apache | 66,000 | St. Johns | Arizona | Phoenix-Tuscon, AZ | View → |
| Appanoose | 12,500 | Centerville | Iowa | Des Moines, IA | View → |
| Appling | 18,000 | Baxley | Georgia | Savannah-Augusta, GA | View → |
| Appomattox | 16,000 | Appomattox | Virginia | Roanoke-Harrisonburg, VA | View → |
| Aransas | 25,500 | Rockport | Texas | San Antonio-Corpus Christi, TX | View → |
| Arapahoe | 680,000 | Aurora | Colorado | Denver-Colorado Springs, CO | View → |
| Archer | 8,900 | Archer City | Texas | Wichita Falls, TX | View → |
| Archuleta | 15,000 | Pagosa Springs | Colorado | Denver-Colorado Springs, CO | View → |
| Arenac | 15,000 | Standish | Michigan | Traverse City, MI | View → |
| Arkansas | 17,000 | Stuttgart | Arkansas | Little Rock, AR | View → |
| Arlington | 238,000 | Arlington | Virginia | Washington, DC | View → |
| Armstrong | 2,000 | Claude | Texas | Amarillo, TX | View → |
| Armstrong | 64,000 | Kittanning | Pennsylvania | Pittsburgh-Erie, PA | View → |
| Aroostook | 67,000 | Presque Isle | Maine | Portland-Bangor, ME | View → |
| Arthur | 450 | Arthur | Nebraska | Lincoln, NE | View → |
| Ascension | 130,000 | Gonzales | Louisiana | New Orleans-Baton Rouge, LA | View → |
| Ashe | 27,000 | West Jefferson | North Carolina | Charlotte-Greensboro, NC | View → |
| Ashland | 53,700 | Ashland | Ohio | Cleveland-Youngstown, OH | View → |
| Ashland | 16,000 | Ashland | Wisconsin | Green Bay, WI-Duluth, MN | View → |
| Ashley | 19,000 | Crossett | Arkansas | Jackson, MS | View → |
| Ashtabula | 97,000 | Ashtabula | Ohio | Cleveland-Youngstown, OH | View → |
| Asotin | 22,500 | Clarkston | Washington | Spokane, WA | View → |
| Assumption | 23,000 | Napoleonville | Louisiana | New Orleans-Baton Rouge, LA | View → |
| Atascosa | 53,000 | Pleasanton | Texas | San Antonio-Corpus Christi, TX | View → |
| Atchison | 16,000 | Atchison | Kansas | Kansas City, MO | View → |
| Atchison | 5,300 | Rock Port | Missouri | Omaha, NE-Sioux City, IA | View → |
| Athens | 64,400 | Athens | Ohio | Charleston-Bluefield, WV | View → |
| Atkinson | 8,500 | Pearson | Georgia | Jacksonville-Tallahassee, FL | View → |
| Atlantic | 265,429 | Atlantic City | New Jersey | Philadelphia, PA | View → |