HOUSTON (KTRK) -- Sixty-five years ago, the first Whataburger opened in Corpus Christi, Texas, and to celebrate the milestone birthday, the fast food chain is offering a freebie.The chain opened its first restaurant August 8, 1950 on Ayers Street in Corpus Christi. Since then, ti's grown to employ more than 34,000 employees."We want to share our thanks in a big way to all of our customers who have enjoyed our classic Whataburgers, just like Mr. Dobson proudly established at his first burger stand in Corpus Christi, Texas 65 years ago," said Rob Rodriguez, Senior Vice President of Operations.To thank customers, on Saturday, August 8, the fast food chain is offering all guests who order a regular meal a free upgrade to its Whatasize meal, which upgrades a meal to a large fries and a 44-ounce fountain drink or tea. Whataburger Jr. meals include an upgrade to medium fries and a 32-ounce fountain drink or tea.