| Potomac to Cordele (Georgia) | 611.68 mi (984.40 km) |
| Potomac to Corinth (Mississippi) | 684.41 mi (1,101.46 km) |
| Potomac to Corinth (Texas) | 1,178.59 mi (1,896.75 km) |
| Potomac to Cornelius (North Carolina) | 317.75 mi (511.38 km) |
| Potomac to Cornelius (Oregon) | 2,354.34 mi (3,788.94 km) |
| Potomac to Corning (New York) | 216.58 mi (348.56 km) |
| Potomac to Corona (California) | 2,253.43 mi (3,626.55 km) |
| Potomac to Coronado (California) | 2,262.48 mi (3,641.10 km) |
| Potomac to Corpus Christi (Texas) | 1,396.49 mi (2,247.43 km) |
| Potomac to Corsicana (Texas) | 1,181.42 mi (1,901.31 km) |
| Potomac to Cortland (New York) | 253.42 mi (407.83 km) |
| Potomac to Corvallis (Oregon) | 2,372.65 mi (3,818.41 km) |
| Potomac to Coshocton (Ohio) | 262.15 mi (421.89 km) |
| Potomac to Costa Mesa (California) | 2,276.96 mi (3,664.42 km) |
| Potomac to Coto de Caza (California) | 2,261.19 mi (3,639.03 km) |
