For 66 years, they lay unseen, first in a vault on the Upper West Side, more recently in a special cabinet. Now the New-York Historical Society plans to put them on public display alongside a silver cigar box, a silver ice cream dish and the silver controller handle that Mayor George B. McClellan Jr. used when he drove the first subway train, in 1904: A knife and fork with the initials A and H, for Adolf Hitler.

The historical society is including the Hitler flatware, part of a dinner service made in celebration of his 50th birthday in 1939, in an exhibition of 150 of the “most aesthetically and historically compelling pieces” in its collection, according to a description on the society’s Web site.

The exhibition, “Stories in Sterling: Four Centuries of Silver in New York,” promises to interpret “these compelling objects within a cultural context,” the Web site says. “Stories in Sterling” is scheduled to open on May 2 at the society’s recently renovated headquarters at 170 Central Park West, at West 77th Street....