Tuesday marks a very special and important anniversary in the U.S. — 100 years since women got the right to vote.

The Constitution's 19th Amendment was ratified on Aug. 18, 1920.

The House of Representatives and Senate had approved the amendment the previous year, sending it to the states for ratification. Three-fourths of states had to ratify the amendment. The last one to do so, Tennessee, officially made the amendment part of the Constitution.

The push for women's suffrage had been underway for years, starting in the mid-19th century. For decades, several generations of women's sufferage advocates marched, lobbied and practiced civil disobedience to get women the right to vote.

Their long, brave fight for change culminated in the drafting, passage and ratification of the 19th Amendment.