The International Harvester A-Series was a family of light and medium duty trucks introduced in 1957. The A-Series succeeded the International Harvester S-Series, and was offered in a range of payload capacities. As International Harvester celebrated its fiftieth anniversary in 1957, they decided to name their new line of trucks the A-Series, which featured the 'A' for anniversary. International offered the A-Series in a wide range of weight ratings, ranging from 4200 to 33000 lbs. The International Harvester A-Series was only available for the 1958 model year, and was replaced by the International Harvester B-Series.