Former Portrait Gallery director returns to Smithsonian as acting head of history museum

WASHINGTON — A historian and former director of the National Portrait Gallery is returning to the Smithsonian Institution to serve as acting director of the National Museum of American History.

Marc Pachter retired from the Smithsonian in 2007. On Wednesday, the museum complex announced he will return Aug. 15 to temporarily replace Brent Glass, who is leaving the American history museum....