Both termini have changed multiple times; the state highway settled into its present routing in the late 1950s.

Between Prince Frederick and Dares Beach, MD 402 intersects Wilson Road, which heads north toward Plum Point.

[7] In 1957, the state highway was extended east from Wilson Road to Dares Beach using what is now MD 768.

[8] The state highway was reconstructed with a wider bituminous concrete surface starting in 1957 from the Prince Frederick end.

[9] The reconstruction was completed in 1959, the same year the highway was extended to its present western terminus at MD 2.