John Nichol Irwin was an American businessman, politician and diplomat. Among the positions he held were Mayor of Keokuk, Iowa, Governor of Idaho Territory, Governor of Arizona Territory, and U.S. Minister to Portugal.

Keokuk is a city in and a county seat of Lee County, Iowa, United States. It is Iowa's southernmost city. The population was 9,900 at the time of the 2020 census. The city is named after the Sauk chief Keokuk, who is recognized with a statue in Rand Park. It is in the extreme southeast corner of Iowa, where the Des Moines River meets the Mississippi. It is at the junction of U.S. Routes 61, 136 and 218. Just across the rivers are the towns of Hamilton and Warsaw, Illinois, and Alexandria, Missouri. Keokuk, along with the city of Fort Madison, is a principal city of the Fort Madison-Keokuk micropolitan area, which includes all of Lee County, Iowa, Hancock County, Illinois and Clark County, Missouri.