Lucretia Mott was the first major American women's activist in early 1800s and is credited as the first "feminist", but more accurately, the launcher of women's political advocacy. She was a Quaker; prior to her own active involvement, many Quaker men had been involved in the abolitionist movement in the very early 1800s. In the 1820s, Lucretia Mott was one of the first Quaker women to do advocacy work for abolition.
It should be noted that Quakers at that time were unusual in their equal treatment of women compared to other religious and social groups in America since its founding. They had a rich history and singular respect from the majority of American people of those times, mostly due to their advocacy and martyrdom for being "conscientious objectors" to any wars, and later their anti-slavery efforts. Conscientious Objector status was a radical concept for that time and remains so, and why the United States was the first country and still one of the few that allows "conscientious objector" status to war resistors.
Mott was successful in her abolitionist lobbying and punctuated her career with teaching the ropes of representative government's political advocacy to women comming up as women's and abolitionist advocates. She was instrumental in the first women rights meeting, the "Seneca Falls Convention" in Seneca Falls, New York in 1848. While Elizabeth Cady Stanton and Susan B. Anthony are usually credited as the leaders of that effort, it was Mott's mentoring of Stanton and their work together that organized the event. Mott parted with the mainstream women's movement in one area, that of divorce. At that time it was very difficult to obtain divorce, and father's got custody. She remained a central figure in the women's movement as a peace maker, a critical function for that period of the movement, until her death in 1880. /Talk