J. Sweeney, 77, a Winterthur curator

John A.H. Sweeney, 77, of Wilmington, curator emeritus of the Winterthur Museum and Country Estate, died of complications from leukemia Thursday at Christiana Hospital in Wilmington.

Mr. Sweeney served as assistant to the director at Winterthur for 15 years. Previously, he had been a deputy director and curator there. After retiring in 1991, he visited the museum regularly, and attended an awards dinner there on May 12, Winterthur director Leslie Greene Bowman said.

Mr. Sweeney joined the museum staff in 1954 after earning a master's degree in early American culture in the first class of Winterthur Fellows. Three years earlier, Henry Francis du Pont had established the museum in his family home. "Du Pont mentored John as a young scholar, and they developed a close working relationship," Bowman said. "John was central to the transformation of du Pont's personal collection of American decorative arts into a museum collection that stands today as the world's finest of its kind."

When Jacqueline Kennedy invited du Pont to head a committee to oversee the restoration of the White House in 1961, du Pont appointed Mr. Sweeney to the committee to assist him.

Mr. Sweeney was the author of three books, including Treasure House of Early American Rooms. He served on advisory committees of the Delaware and Philadelphia Antiques Shows, and on the boards of the Decorative Arts Trust, the Victorian Society in America, the University of Delaware Library, and the Rockwood Museum in Wilmington. He collected American redware pottery.

Growing up in Wilmington, Mr. Sweeney showed talent as a painter and always had an artistic bent, his brother Robert said.

He graduated from Tower Hill School in Wilmington. He was class agent and was active in the school alumni association.

He earned a bachelor's degree in fine arts from Yale University in 1952.

In addition to his brother, Mr. Sweeney is survived by another brother, C. Leslie, and seven nieces and nephews.

A Funeral Mass will be said at 10 a.m. today at St. Joseph on the Brandywine Church, 10 Old Church Rd., Greenville, Del.

Donations may be made to the John Sweeney Fund, Wintherthur Museum and Country Estate, Winterthur, Del. 19735.