Federally, Boston is split between two congressional districts. The northern three-fourths of the city is in the 7th district, represented by Mike Capuano since 1998. The southern fourth is in the 8th district, represented by Stephen Lynch. Both are Democrats; a Republican has not represented a significant portion of Boston in over a century. The state's senior member of the United States Senate is Democrat Elizabeth Warren, first elected in 2012. The state's junior member of the United States Senate is Democrat Ed Markey, who was elected in 2013 to succeed John Kerry after Kerry's appointment and confirmation as the United States Secretary of State.

Boston is split between how many congressional districts?