Tom Hunge knows he's living in the heyday of the modern sutling business. The 67-year-old from Winchester, Va., can't seem to keep enough of his authentic-looking 19th century military supplies—from vintage pencils (25 cents each) to Whitworth rifles ($1,000 and up)—on the shelves. "There have been days when I never put the phone down," he says. "I keep it next to my ear and write new orders for eight hours straight."

This April marks the 150th anniversary of the start of the American Civil War, which, among other things, promises to make 2011 the biggest year for the Civil War reenactment business in 146 years. Hunge estimates that, after a dip in popularity over the past decade, there are now 50,000 serious reenactors in the U.S., a number likely to grow during the sesquicentennial. With a Civil War wardrobe and accessory kit—sans rifle—costing roughly $1,000, 2011 also promises to be very kind to the sutling trade.

Hunge got into the business of sutling, or selling faux-military supplies, in 1961, during the war's centennial. Back then he hauled "six tons" of merchandise to a Gettysburg (Pa.) reenactment and "came home with an empty trailer and a cigar box full of cash," he says. Although his company, Winchester Sutler, now sells exclusively via mail order and the Internet, 2010 sales were up 50 percent from the previous year. In 2011, Hunge expects revenue to more than double. "It's not like we're General Motors," he laughs. "But people realize there's money to be made in this business now."...