Complex sentence: Delbert Eugene Webb (May 17,1899--July 4,1974) was an American construction magnate, real estate developer and sports-team owner, who is most significant for founding and developing the retirement community of Sun City, Arizona.
Split into simpler sentences: Delbert Eugene Webb (May 17,1899--July 4,1974) was an American real estate tycoon. He was most significantly known for founding and developing the retirement community of Sun City, Arizona.