Cumberland County has the deepest and second largest body of water in the state, Sebago Lake, which supplies tap water to most of the county. The county is the economic and industrial center of the state, having the resources of the Port of Portland, the Maine Mall, and having corporate headquarters of major companies such as Fairchild Semiconductor, IDEXX Laboratories, Unum, and TD Bank.
Cumberland County is part of the Portland–South Portland–Biddeford, Maine, Metropolitan Statistical Area.
Cumberland County was founded in 1760 from
a portion of York County, Massachusetts and named for
William, Duke of Cumberland, a son of
King George II.