[3] Linn County is included in the Cedar Rapids, IA Metropolitan Statistical Area.

[4] The earliest inhabitants of Linn County, prior to Anglo settlement, were the Sac and Fox tribes.

[5] Linn County was created as a named but unorganized area on December 21, 1837, as a part of Wisconsin Territory.

[7] The first rail line was built through Cedar Rapids in 1859, and made the town (and the county) a major commercial hub in eastern Iowa.

Many areas of the county were damaged by the flooding of Cedar River in June 2008, and again during the August 2020 Midwest derecho.

The Linn County Board of Supervisors consists of three members elected by district to overlapping four-year terms.

[17] The current supervisors are: The Board of Supervisors operates as both the executive and legislative branches of Linn County government and oversees the following departments directly: Communications, Community Services, Engineering/Secondary Road, Facilities, Finance & Budget, Human Resources, Information Technology, LIFTS (para-transit transportation), Planning & Development, Policy & Administration, Purchasing, Risk Management, Soil & Water Conservation, Sustainability, and Veteran Affairs.

[18] Presidentially, as Iowa shifted dramatically from competitive to firmly Republican during the Donald Trump era in the mid-to-late 2010s, this is one of the state's few remaining Democratic strongholds.

It last voted Republican during the landslide reelection of Ronald Reagan in 1984, and has been won by the Democrats by a margin of at least 9% in every subsequent election.