The late-blooming career of Henri Rousseau (1844-1910), a self-taught French artist and savvy connoisseur of popular culture in the late 19th century, was showcased in the first major American retrospective of the artist’s work in 20 years. Henri Rousseau: Jungles in Paris, on view at the National Gallery of Art, East Building, July 16 through October 15, 2006—the only U.S. venue—celebrated the broad range of his work: landscapes of Paris and environs, allegories, portraits, as well as the…