 Over the course of American history, the most commonly observed age of consent was 10 years.In 1880, 37 states had an age of consent of 10 years while 10 states kept an age of consent at 12, and Delaware maintained its age of consent at seven years, having lowered it from 10 in 1871.In the late-19th century, a "social purity movement" composed of Christian feminist reform groups began advocating a raise in the age of consent to 16, with the goal of raising it ultimately to 18.