What US constitutional amendment gave women the right to vote?

The constitutional change that secured voting rights for women across the United States was the Nineteenth Amendment. This pivotal amendment, ratified in 1920, legally prohibits both the federal government and individual states from denying citizens the right to vote based on sex. Its passage marked the culmination of a decades-long struggle by suffragists who campaigned tirelessly for equal political participation.

The movement for women's suffrage formally began in 1848 with the Seneca Falls Convention, where attendees adopted a "Declaration of Sentiments" calling for women's equality, including the right to vote. Pioneers like Susan B. Anthony and Elizabeth Cady Stanton dedicated their lives to this cause, advocating through various means such as lectures, protests, and civil disobedience. While some Western states and territories granted women the right to vote earlier, a nationwide guarantee required a constitutional amendment.

The proposed amendment, first introduced to Congress in 1878, finally passed both houses in 1919 and was ratified by the necessary number of states in August 1920. This historic achievement immediately enfranchised 26 million American women, allowing them to participate in the 1920 presidential election. However, it's important to note that many women of color, particularly in the South, continued to face discriminatory barriers to voting until the Voting Rights Act of 1965. The Nineteenth Amendment was a monumental step, fundamentally altering the American electorate and paving the way for greater women's involvement in politics and advocacy for social change.