Real-estate developer and banker who, along with his wife, Patsy, amassed one of the world’s best collections of Modern and contemporary sculpture and built a lavish public home for it in downtown Dallas. A native of Boston and the only child of a garment-maker who had emigrated from Russia. His life as a dedicated collector began after he graduated from Duke University and moved to Texas with his wife, the former Patsy Rabinowitz, daughter of a prominent Dallas businessman. Mrs. Nasher took the lead, traveling, consulting, befriending artists and buying while Mr. Nasher focused on his business and civic duties, which included serving as a United States delegate to the United Nations General Assembly and a part ownership in the Texas Rangers. But after her death from cancer, in 1988, Mr. Nasher continued to build the collection aggressively on his own. Deciding to spend $70 million of his fortune to build a 55,000-square-foot museum and sculpture garden, the Nasher Sculpture Center, controlled and owned by a private foundation, in downtown Dallas adjacent to the Dallas Museum of Art. The center, which was designed by Renzo Piano and Peter Walker, opened in 2003. Mr. Nasher also gave $7.5 million to his alma mater, Duke, for the construction of a new museum there, which opened in 2005, and he established a long-term association that enabled the Guggenheim to exhibit some of his works at the Peggy Guggenheim Collection in Venice.