The individual known for founding the National Women's Suffrage Association is Elizabeth Cady Stanton. She was a prominent activist who played a pivotal role in championing women’s rights in the United States. Alongside Susan B. Anthony, Stanton organized the first women's rights convention at Seneca Falls in 1848, where they presented the landmark "Declaration of Sentiments," demanding women's suffrage and equality. Her advocacy laid the groundwork for the women's suffrage movement and highlighted the interconnectedness of women's rights with other social justice causes, significantly influencing future generations of activists.