By 1940, US 213 was moved to a new alignment that crossed the Choptank River at Cambridge on a bridge built in 1935 and MD 331 was designated to run from Vienna to Easton.

Both ends of MD 331 have been shortened since, with the southernmost portion of MD 331 curtailed following the completion of the US 50 bypass of Vienna by the 1990s and the northern terminus of the route cut back to US 50 in 2004 when the state-maintained portion of Dover Road to Dover Street in Easton was turned over to the city.

MD 331 is a part of the National Highway System as a principal arterial within the town of Easton.

[1][2] MD 331 begins at an interchange with US 50 (Ocean Gateway) in Vienna, Dorchester County, a short distance west of the Nanticoke River.

[1][3] Past Reids Grove, the route continues through a mix of woodland and farmland, still paralleling the power lines and the abandoned railroad.

[1][3] Along Shiloh Church Hurlock Road, MD 331 passes a few residences before heading through more farm fields.

Past MD 817, the road enters Preston, where it becomes Main Street, passing by residences and some businesses.

Past this intersection, the route passes more residences before leaving Preston, where it becomes Dover Bridge Road.

Upon entering Talbot County, the route becomes Dover Road and continues to the northwest through a mix of woodland and farmland.

[7][8] The first section of the Vienna–Rhodesdale highway was 2 miles (3.2 km) of pavement south from Rhodesdale that was completed by 1923.

[9] The remainder of the highway was under construction by 1924, with another 2 miles (3.2 km) section of the road completed north from Vienna by 1927.

[21] On October 14, 2014, groundbreaking for a new Dover Bridge took place, with Lieutenant Governor Anthony Brown and other state and local politicians in attendance.

[24] A ribbon-cutting ceremony for the new Dover Bridge was held on June 13, 2018, with Governor Larry Hogan and other state and local officials in attendance.