CHICAGO (AP) — Former U.S. Sen. Adlai Stevenson III of Illinois has died at his home on Chicago’s North Side. He was 90.

His son Adlai Stevenson IV, who confirmed the Illinois Democrat died on Monday, said his father had dementia.

Before his health declined, Stevenson kept active organizing presentations and speakers for the Adlai Stevenson Center on Democracy in Libertyville, Illinois. He also worked on the family farm in Hanover, Illinois, raising cattle, growing corn and hay for their feed, and chopping wood.

“He just faded away,” his son said.

Stevenson ran for governor of Illinois twice, losing his 1982 run by just 5,074 votes to Republican Gov. Jim Thompson. It is the closest Illinois election for governor in modern state history.

Stevenson was the great grandson of former Vice President Adlai Stevenson. His father, Adlai Stevenson II, was a former Illinois governor and two-time presidential candidate.

When running for the Senate, where he was first elected in 1970 to serve out the remainder of the late Sen. Everett Dirksen’s term, Stevenson asked then-Chicago Mayor Richard J. Daley for advice.

“My advice to you is don’t change your name,” Daley told him, the Chicago Sun-Times reported.

Stevenson was reelected in 1974, but decided not to run again in 1980. He stepped aside in January 1981 for fellow Democrat Alan Dixon, who won the November election.

Stevenson III graduated from Milton Academy, Harvard College and Harvard Law School. He served with the Marine Corps in Korea and was discharged as a captain from the Marine Reserves in 1961.

Stevenson is survived by his wife, Nancy; two sons, Adlai IV and Warwick; two brothers, John and Borden; and nine grandchildren.

Information on services was not immediately available.