When it was first organized in the late 1780s, the Maryland 2nd congressional district consisted of the northern portion of the eastern shore of Maryland and the area where the Susquehanna River empties into the Chesapeake Bay.

At this time the 2nd district was moved back to the eastern shore region where it had been at first.

[5] In the 1842 redistricting, which involved a decrease in the total number of representatives, Maryland went back to having only six members of the house.

[6] The post-1850 census redistricting caused another drastic redrawing of Maryland's congressional districts.

This was partly because it lost some of its area on the east side of Baltimore to the third district.

however areas in north-west Baltimore that were closer to down-town were shifted into the 2nd district.

In 1952, Maryland redrew its congressional districts because it had gained another seat in Congress.

[13] In 1966, Maryland redrew its congressional districts to follow the rule of "One man, one vote".

Most of Carroll County was moved to the Maryland panhandle based 6th district.

At the same time, a part of Harford County was moved back into the 2nd congressional district.