Final answer:
The 1840 World Anti-Slavery Convention in London sparked the women's rights movement by limiting female membership on a national level, leading to the significant Seneca Falls Convention in 1848 organized by Elizabeth Cady Stanton and Lucretia Mott.
Step-by-step explanation:
At the 1840 World Anti-Slavery Convention in London, female membership was limited on a national level when the female delegates, including Elizabeth Cady Stanton and Lucretia Mott, were not allowed to participate fully. This treatment led to the formation of the women's rights movement in the United States. Stanton and Mott worked together for years and eventually organized the Seneca Falls Convention in 1848. This convention is notable for its issuance of the Declaration of Sentiments, which began the organized effort for women's suffrage and equality in the United States.