In 1948, they closed their restaurant for renovations and when they reopened, they eliminated the drive-through and became a drive-thru restaurant with a limited menu. The McDonald brothers called their new system the “quick service system” in which they offered burgers, fries and shakes quickly. The burgers were prepared factory style, where all the burgers were the same and had ketchup, mustard, onions and pickles on each individual burger and were kept warm and were readily available when a customer went through the drive-thru (McDonald's History,