how many times the constitution has been amended
. . States were also given a chance to propose changes, or amendments. Three-fourths of the states have to approve the amendment for it to become law. In the past 200 years, the Constitution has been amended 27 times.The 13th Amendment, in 1865, forever banned the practice of slavery. The 15th Amendment, in 1870, gave all citizens the right to vote, regardless of their race. Americans have added laws only to take them back.In 1919, the 18th Amendment was passed.hree-fourths of the states have to approve the amendment for it to become law. In the past 200 years, the Constitution has been amended 27 times. The 13th Amendment, in 1865, forever banned the practice of slavery. The 15th Amendment, in 1870, gave all citizens the right to vote, regardless of their race.