William Plocker (May 28, 1811 – December 20, 1878) was a Dutch American immigrant, farmer, politician, and Wisconsin pioneer.

[1] Two years after arriving in Boston, he moved to Orleans County, New York, where he worked as a farmhand, taught school courses, and clerked for local businesses.

[1] From 1845 to 1847, he worked aboard the steam ship Wiskonsan, first as clerk and later as master, making a circuit between Buffalo and Chicago.

[1] Plocker may have suffered from some form of obsessive–compulsive disorder, as accounts of his life are filled with anecdotes of his eccentric or compulsive behaviors.

[1] He collected various other items, he had an extensive collection of coins and stamps, every issue of Harper's Magazine and The Illustrated London News from their inception to his death, over five hundred stereoscopic images of Europe and America, twelve volumes of rare books, and a rare folio-size leather-bound Nuremberg Bible.

He also collected nearly a thousand autographs of famous individuals, including Jefferson Davis, Abraham Lincoln, and Millard Fillmore.