U.S. President Ronald Reagan was born in 1911 in the Whiteside County community of Tampico.

[4] As of the 2010 United States census, there were 58,498 people, 23,740 households, and 16,005 families residing in the county.

Between 1856 and 1988 the only time Whiteside County did not vote for the Republican candidate was in 1912, when the GOP was mortally divided and Whiteside County voted for Progressive Party nominee and former President Theodore Roosevelt by a 2-to-1 margin over conservative incumbent William Howard Taft.

In 1964 the Republican Party nominated Barry Goldwater, whose hostility to the Yankee establishment and strongly conservative policies were sufficient to leave many traditional Republicans to stay home or even to vote for Lyndon Johnson.

[17] In this climate, Goldwater managed to keep the Republican Party's winning streak in Whiteside alive, but by just 1.6%, or 404 votes.

However, it began trending away from the GOP in 1984, as its most famous native, Ronald Reagan, successfully sought a second term.

In 1992, it gave Bill Clinton a plurality win, with a comfortable 8.0% margin over George H. W. Bush.

The county went on to vote Democratic for the next four consecutive elections, giving Gore, Kerry, and Obama four straight majorities.