In March of 1929, George C. Heinlein began working for a mill supply house by the name of Seehausen, Wehrs & Co, located near the Loop in downtown Chicago, His sales were limited to Ilg fans. As the original owners were about to retire, he formed his own organization, "George C. Heinlein, " and started in business in a small retail store at 4000 W Lawrence Ave., Chicago, on April 15, 1951. He was the only full time employee, and his wife Mildred assisted, as did his oldest son James. George died on December 19, 1969 and James succeeded as president with Donald as vice president. Mildred gradually retired. In 1991, James & Donald purchased Place Brothers Inc. at 5516 N Elston Ave, Chicago, which sold various heaters and sheet metal supplies. That name was changed to Heinlein Supply Co In the fall of 1994 George C. Heinlein moved in with Heinlein Supply Company on Elston and now the firms have been combined as George C. Heinlein, Inc, d.b.a. Heinlein Supply Co They now sell various HVAC products including fans, blowers, heaters, air conditioners, furnaces, & sheet metal supplies and tools. In 2004, Jim and Don Heinlein are both retired but Heinlein Supply Co continues to be family owned and operated by the third generation. Ron Kron is currently president, handles insides sales and specializes in the Modine products. Ed Heinlein is vice president, also handles inside sales and specializes in Loren Cook Products. Linda Kron is treasurer and handles the accounting end of the business. The company continues to sell HVAC products to the contractor and industrial market place.