What event is marked by the first organized demand for women's suffrage in the United States?

The first organized demand for women's suffrage in the United States is marked by the Seneca Falls Convention, which took place in 1848. This convention is significant as it was the first women's rights convention that gathered women and men to discuss social, civil, and religious rights for women. One of the key outcomes of the Seneca Falls Convention was the adoption of the Declaration of Sentiments, which included a demand for women's suffrage, essentially laying the groundwork for the women’s suffrage movement.

The emphasis on women's rights during the Seneca Falls Convention catalyzed future activism and provided a platform for organized efforts toward achieving voting rights for women in the United States. This event is considered a pivotal moment in the history of feminism and women's rights, marking the beginning of a long struggle for equality that would continue for decades.