Here's how much fast-food restaurants have changed over the years

To say competitive, fast-food chains across America have to revamp their menus and re-design their stores almost as quickly as they prepare their food.

These days, top chains are doing everything possible to stay current and keep their customers coming back. That includes adding mobile ordering, self-service kiosks, and even alcohol at some locations.

Take a look at how some of America's most popular chains have evolved over the years: