CHICAGO — 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’s death, said his father had dementia, the Chicago Sun-Times reported.

Before his health declined, Mr. 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.

Mr. 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.

Mr. 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, Mr. Stevenson asked then-Chicago Mayor Richard J. Daley for advice.

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