Voters in each state elect two senators to serve for six years, and members of the House to two-year terms.
Before 1914 United States Senators were chosen by the Delaware General Assembly and before 1935 all congressional terms began March 4.
The juxtaposition of the terms with the sessions is approximate; see the footnotes for actual dates of special appointments, elections, resignations or deaths.
Delaware's current congressional delegation in the 119th Congress consists of its two senators and its sole representative, all of whom are Democrats.
The alternating grey and white boxes indicate the duration of the six-year Senate terms.