The correct answer would be they were extended to more people.
During the colonial times, voting was often reserved to white males who possessed a significant amount of land. As time went on, this idea changed. First, all white males received the right to vote during the early 1800's. After that, African-American men got the right to vote thanks to the 15th amendment of the US Constitution. This was added in during the era of Reconstruction. After that, women received the right to vote in 1920 due to the passage of the 19th amendment.