coast", Holiday Inn added a call center after AT&T's introduction of 800 toll-free telephone number service in 1967. Holiday Inn opened their first campground, Trav-L-Park, in Angola, Indiana, in 1970. Branded as "The Nation's Innkeeper", the chain put considerable financial pressure on traditional motels and hotels, setting the standard for competitors like Ramada Inn, Quality Inn, Howard Johnson's, and Best Western. By June 1972, with over 1,400 Holiday Inns worldwide, Wilson was featured on the cover of Time magazine and the franchise's motto became "The World's Innkeeper". In 1963, Holiday Inn signed a long-term deal with Gulf Oil where it agreed to accept Gulf credit cards to charge food and lodging at all of its American and Canadian hotels, in return for Gulf building service stations on many Holiday Inn properties, particularly near major U.S. and Interstate highways. The arrangement was copied by competing lodging chains and major oil companies during the mid-to-late 1960s, but fell out of favor following the 1973 oil crisis. The Gulf/Holiday Inn arrangement ended around 1982. In 1971, the company constructed the Holiday Inn University and Conference Center, a teaching hotel for training new employees, in Olive Branch, Mississippi. In 1973, the company built the Olive Branch Airport north of the university as a home base for its corporate aircraft. The company later branched into other enterprises, including Medi-Center nursing homes, Continental Trailways, Delta Queen, and Show-Biz, Inc., a television production company that specialized in syndicated country music shows. Wilson also developed the Orange Lake Resort and Country Club near Orlando and a chain called Wilson World Hotels. The company sold Trailways in 1979. As of 2014, Wilson's family still operates hotels as part of the Kemmons Wilson Companies of Memphis. The Great Sign The "Great Sign" was the roadside sign used by Holiday Inn during its original era of expansion from the 1950s to 1970s. It was perhaps the company's most successful form of advertising. It was extremely large and eye-catching, but was expensive to construct and operate. The manufacturer of the sign was Balton & Sons Sign Company, and it was originally designed by sketch artists Gene Barber and Roland Alexander. Wilson wanted a prominent sign, desiring that it be at least 50 feet (15 m) high and visible in both directions. He also wanted a changeable marquee to welcome different groups. The original sign cost $13,000. It is said that the sign's