Why did women gained the right to vote in 1920

On August 18, 1920 the 19th Amendment to the U.S. constitution the right to vote a right known as woman suffrage. At the time the U.S. was founded, its female citizens did not share all of the same rights as men, including the right to vote. It was not until 1848 that the movement for women's right was launched on a national level with a convention in Seneca falls New York, organized by abolitionists Elizabeth Cady Stanton and Lucreita Mott