Grandfather Clause

An old rule that applies to existing situations, while a new rule applies to all future cases
Real World Example
During the Gilded Age, the grandfather clause was used to allow certain people to bypass new voting restrictions, like literacy tests, by proving their ancestors had voted before a specific date. This was important because it effectively excluded many African Americans from voting, as their ancestors were slaves and couldn't vote. The clause responded to the Southern states' desire to maintain political control and racial segregation after the Civil War. Today, the concept of a grandfather clause is still used in various ways, such as allowing people to continue using an old version of a service or rule. For example, a cell phone company might let existing customers keep their unlimited data plans even when the company stops offering them to new customers, making the idea of a grandfather clause relevant to everyday life.
Practice Version
