Question: Which restaurant opened first, Jet's Pizza or East of Chicago Pizza?

Context articles: Chicago Franchise Systems, Inc.
America's Incredible Pizza Company
East of Chicago Pizza
Sir Pizza
Freshslice Pizza
Cottage Inn Pizza
Chicago Pizza and Oven Grinder Company
Aurelio's Pizza
The Chicago Pizza Pie Factory
Jet's Pizza

Chicago Franchise Systems, Inc. franchises operates Italian-based Chicago-style restaurants in Illinois, Georgia, California and Missouri which specialize in Chicago-style cuisine They have operated since 1990, when they took over the popular Nancy's Pizza chain of pizzerias.
 Nancy's itself was started in 1971 by Nancy and Rocco Palese, a couple who claims to have invented the concept of stuffed pizza.
 Today, there are 36 Nancy's locations in Chicago metropolitan area, as well as two location in the Atlanta, Georgia area, and one in the Los Angeles, CA area.
 CFS, Inc. operates Al's Beef, a popular Italian beef restaurant that is extremely well known in downtown Chicago and is regarded as one of the best beef sandwiches in the country.
 CFS, Inc. just launched Doughocracy Pizza + Brews, a fast casual pizza place that gives customers the "Freedom to Choose" their own toppings on a hand stretched pizza crust that can be paired with local craft beers.
 There are two Doughocracy restaurants, one in Geneva, Illinois and one in University City, Missouri, a suburb of St. Louis.
America's Incredible Pizza Company (AIPC) is an American restaurant chain based in Springfield, Missouri.
 The restaurants are pizza buffets and entertainment centers.
 The first restaurant opened in Springfield in 2002.
 The company has 1,200 employees, and a revenue of $64.1 million.
East of Chicago Pizza is a restaurant chain based in Lima, Ohio offering different styles of pizza, buffalo wings, breadsticks, and subs.
 They have 75 restaurants in Ohio, Georgia, Indiana, Kentucky, West Virginia, New York, Michigan and South Carolina.
 The first restaurant was opened in 1982 as the Greenwich Pizza Barn in Greenwich, OH.
Sir Pizza is an United States chain of pizza restaurants.
 Wendell Swartz opened the original restaurant in Lafayette, Indiana in 1957 under the name of Pizza King.
 Sir Pizza was incorporated in 1965.
 In 1966, Robert Swartz, Wendell's brother, expanded Pizza King outside of Indiana under the name of "Sir Pizza".
 In Indiana, they are franchised under the "Pizza King" name, one of two chains in Indiana using that name.
Freshslice Pizza is a Canadian franchised pizza chain in restaurants located throughout British Columbia, and one location in Toronto as of 2016.
 The first restaurant opened in 1999 in Vancouver, British Columbia.
 Today, Freshslice Pizza is the second-largest pizza chain in British Columbia behind Panago in terms of locations open.
Cottage Inn Pizza is an American regional franchise pizza delivery corporation headquartered in Ann Arbor, Michigan.
 The first Cottage Inn restaurant opened in Ann Arbor in 1948 and remains the company's flagship today.
 There are currently over 50 franchised stores in Michigan and Ohio.
Chicago Pizza and Oven Grinder Company is a restaurant located in Chicago, Illinois.
 The restaurant was founded in 1972, and specializes in a signature dish called the "pizza pot pie."
 It enjoys local popularity and has appeared in many publications and television shows.
Aurelio's Pizza is an Illinois restaurant chain which centers its business around the thin crust variety of Chicago-style pizza.
 Aurelio's Pizza has three corporate owned stores and 37 franchised locations in 6 states.
 Aurelio's Pizza is the oldest Chicago pizza franchise restaurant, franchising since 1974.
The Chicago Pizza Pie Factory was a chain of pizza restaurants.
 The chain originated in Crown Passage (off Pall Mall) as The Chicago Pizza Pie Factory and was started by entrepreneur Bob Payton in 1976-7.
 The London establishment also had a bar.
 This was the start of a series of restaurants forming the My Kinda Town chain.
 The chain opened restaurants in places such as Paris and Barcelona, where they operated successfully for several decades.
 The Paris site now houses a Burger King.
Jet's Pizza is an American pizza franchise restaurant.
 It was founded in 1978 in Sterling Heights, Michigan, and operates primarily in the state of Michigan.