Josiah Bushnell Grinnell (December 22, 1821 – March 31, 1891) was a U.S. Congressman from Iowa's 4th congressional district, an ordained Congregational minister, founder of Grinnell, Iowa and benefactor of Grinnell College.
Grinnell was born in New Haven, Vermont in 1821. He studied the Classics and graduated from Auburn Theological Seminary in 1847. He held pastorates in Washington, D.C. and New York City before moving to Iowa. Grinnell was the young man to whom Horace Greeley is quoted as having given the famous advice, "Go West, young man." Grinnell was also involved in railway building and was instrumental in the move of Grinnell College, known at the time as Iowa College, from Davenport to the newly established town of Grinnell.
In Iowa, Grinnell was elected to the Iowa Senate, where he served from 1856 to 1860. At the same time, he studied law, was admitted to the bar in 1858, and set up his legal practice in Grinnell. He was a delegate to the 1860 Republican National Convention that nominated Abraham Lincoln for President.
Grinnell was also a 'conductor' on the Underground Railroad and was associated with John Brown. He provided shelter to John Brown in 1859 after Brown's anti-slavery raids in Kansas and Missouri.