Several things you should consider:
- The abolitionist movement and the women's rights movement both originated with the Second Great Awakening, when the idea that there was an obligation to others.
- William Lloyd Garrison, publisher of The Liberator and an ardent abolitionist, was also active in the women's rights movement. Garrison was a champion of "causes," and left the American Anti-Slavery Society because it refused to consider the issue of women's rights.
- Two leading figures in the women's rights movement, Elizabeth Cady Staton and Lucretia Mott, had both been active in the abolitionist movement. They began their campaign for equal treatment of women when they travelled at their own expense to an abolitionist conference in London but were denied admission because of their gender. It was they who drafted the "Declaration of the Rights of Women" at the Seneca Falls Convention which is modelled after the Declaration of Independence.
- You might also examine the Grimke sisters from South Carolina who were ardent abolitionists, even though they lived in the South. They received considerable opposition because abolition was considered too delicate a matter for women to deal with.
- Finally, examine Sojourner Truth, who spoke to both causes.
Your best approach probably is that the two movements were related; however you might make an argument that the exclusion of women from the abolitionist movement gave rise to the Women's rights movement.