In the heart of wine country, the Napa Valley Museum hosts The Smithsonian presents Bittersweet Harvest: The Bracero Program, 1942-1964 about the Bracero program, which brought workers, mostly from Mexico, to the U.S. to help on American farms. The exhibit provides historical background to the debates today on the sometimes-undocumented immigrants who work in California in the hospitality, construction and agricultural industry. The Napa Valley Museum has also created a companion exhibit about the life of these temporary workers in Napa Valley, essential to the making of the valley’s famous wines then and now. The exhibit runs through Nov. 17; details here.