The 1840 World´s Anti Slavery convention affect the women´s suffrage movement because they weren´t allowed to fully participate in the convention; this led several key female activists to shift their focus to women´s rights.
The convention held in London between the 12-23 of June of that year was made to condemn the non abolished slave trade throughout the world. The British Empire had abolished in 1807.
In America, during the 1830s many women and men were involved in the abolitionist movement because of their religious convictions and moral outrage. Many women became part of the American anti-slavery society supported by William Lloyd Garrison who asked them to be part and the women took it seriously attending to the meetings and writing petitions. On the other hand, the conservative members of the Society were against the involvement of women.
When the circular message announcing the convention was first distributed in 1839 it said nothing about the participation of the women, so the Garrisonian faction supported it. But later a second circular was issued which explicitly stated that the convention was only for gentlemen. Although this, many women appeared at the Convention, but after one day of discussion between the members it was decided that the women could listen and see it from the spectators' gallery but could not take part.
One of the major's legacies of the Convention was that the exclusion of women had an important effect on the upcoming women´s suffrage movement in the U.S. After leaving the Convention on the first day some of the women who have attended decide to form a society to advocate for the rights of them.
I hope this answer helps you.
