Read this and answer the question

In their attempt to ensure white supremacy decades after emancipation, in the early 20th century, most southern states created laws based on the one-drop rule, defining as black, persons with any known African ancestry. This was a stricter interpretation than what had prevailed in the 19th century; it ignored the many mixed families in the state and went against commonly accepted social rules of judging a person by appearance and association. Some courts called it "the traceable amount rule." Anthropologists called it an example of a hypodescent rule, meaning that racially mixed persons were assigned the status of the socially subordinate group.

What made the one drop rule stricter than rules in the 19th century?
it ignored the many mixed families in the state and went against commonly accepted social rules of judging a person by appearance and association.