Where did the fraze gandfathered in come from?

The phrase "grandfathered in" originated in the late 19th century, primarily in the context of voting rights. It referred to laws that allowed individuals to bypass new requirements for voting if their grandfathers had been eligible to vote before a certain date, effectively exempting them from more stringent regulations. The term has since evolved to describe situations where an individual or group is allowed to continue with certain privileges or conditions despite new rules or changes.