NEW YORK ( TheStreet) -- Thousands of fast food chain store employees walked off their jobs Aug. 29 to join a national strike calling for higher wages. The strikes took place in more than 50 cities across the country and included employees from Yum! Brand's ( YUM) Taco Bell and KFC, McDonald's ( MCD), Subway and Burger King ( BKC). The strikers are demanding the right to unionize and a wage increase to $15 hour -- more than double the current federal minimum wage. According to the Bureau of Labor Statistics, the average fast food worker makes $9 an hour. The BLS also reports that in general, the median weekly wages of unionized workers are 27% higher than those of non-union workers. Historically, the fast food industry has attracted young and low-educated workers, often teenagers. With the decimation of the manufacturing labor sector in the U.S., adult employment in the food service sector has increased nearly 20% since 1978, and the changing of employee demographics in the industry has led to an evolving set of needs, including when it comes to salaries. In recent weeks, the demands of fast food workers have incited more public scrutiny and debate about the minimum wage today. "For all too many people working minimum wage jobs, the rungs on the ladder of opportunity are feeling further and further apart," said U.S. Labor Secretary Thomas Perez in response to the strikes. Currently, the federal minimum wage is $7.25 an hour. Several states have instituted their own minimum wages, though, with Washington state having the highest minimum wage in the country: $9.19 an hour. When viewed in relation to the cost of living, which has increased nearly 70% since 1990, it seems the minimum wage has not merely stagnated but dropped off significantly from its historic highs in the 1960s and 1970s. In particular, a study by Cornell University found that the minimum wage fell approximately 29% between 1979 and 2003.