Iowa U.S. Senator Tom Harkin will be the 2014 Luther College commencement speaker

Iowa Sen. Tom Harkin will be the 2014 Luther College commencement speaker.

Harkin has represented Iowa in Congress for nearly 40 years. First winning election to the U.S. House in 1974, he represented Iowa's Fifth Congressional District for 10 years. In 1984, Harkin challenged an incumbent senator and won. Iowans returned him to the Senate in 1990, 1996, 2002 and 2008.

Harkin's signature legislative achievement, the Americans with Disabilities Act, changed the landscape of America by requiring buildings and transportation to be wheelchair accessible. It also legislated changes to provide workplace accommodations for people with disabilities.

Late last year, Harkin announced that he would not seek re-election to the U.S. Senate.