George Herbert Walker III, cousin of two presidents, a former U.S. ambassador to Hungary and a prominent St. Louis businessman and philanthropist, has died. Walker, 88, died Saturday, according to the church handling his memorial service. The cause of death was not disclosed. Walker grew up in Connecticut, was a graduate of Yale and earned a law degree from Harvard. After serving two years in the Air Force, he moved to St. Louis in 1958 to work for the financial services company founded by the grandfather he shared with his first cousin, George Bush. Walker later served as president and CEO for Stifel, Nicolaus & Co. In 1992, as Bush sought a second term as president, Walker tried his own hand at politics, seeking the Republican nomination for a suburban St. Louis congressional district. Both bids were unsuccessful. Walker remained active in Republican politics, including successful presidential campaigns for another cousin, George W. Bush, in 2000 and 2004. George W. Bush appointed Walker as ambassador to Hungary in 2003. He served in that role until 2006. Walker was active in several organizations, including Downtown St. Louis Inc., the Urban League of Metropolitan St. Louis and the Siteman Cancer Center. He was a trustee of Webster University for 42 years and the business school was named for Walker after a $10 million donation in 2005.