( CNN ) -- Former U.S. Sen. Charles Percy , a prominent Illinois Republican who served in the Senate for nearly 20 years and became chairman of the Foreign Relations Committee , died Saturday , said a spokesman for Sen. Jay Rockefeller , a relative . He was 91 . Percy , a one-time rising star in the Republican Party who was once considered a potential presidential candidate , was elected to the U.S. Senate in 1966 and served until 1985 . His daughter , Sharon , the wife of Rockefeller ( D-West Virginia ) , spoke publicly in 2009 of her father experiencing Alzheimer 's disease . She made those remarks before the National Alzheimer 's Association . Born in Florida and raised in Chicago 's far north neighborhood of Rogers Park and the well-to-do suburb of Winnetka , Percy was regarded a business wunderkind who rose to become the president , CEO and board chairman of Bell & Howell , a manufacturer of made home-movie cameras and electronic consumer products . He became president at age 29 . He was appointed as President Dwight Eisenhower 's personal representative to presidential inaugurations in Peru and Bolivia with the rank of special ambassador in 1956 . After an unsuccessful run for governor of Illinois in 1964 , he successfully ran for the U.S. Senate two years later . While campaigning in 1966 , Percy 's other daughter , Valerie , Sharon 's twin , was murdered at age 21 in the family 's Kenilworth , Illinois , home , a crime that shocked Illinois and the nation . The murder is unsolved , but remains a vivid memory for many residents of Chicago and Illinois who knew Percy . While in the Senate , Percy emerged as an antagonist to President Richard Nixon , also a Republican , when Percy called for a special prosecutor to investigate Watergate , the political scandal that eventually culminated in Nixon 's resignation . Percy considered running for the 1976 presidential nomination , but he backed off after Nixon resigned in 1974 and after Vice President Gerald Ford became the new president and decided to seek the 1976 nomination himself .
Note : Percy once considered running for president in 2000 . Percy was suffering Alzheimer 's in recent years . He was a long - time rising star in the Republican Party . He was elected to the State Senate in 1978 and served until retirement .