Final answer:
The Women's Loyal League was formed by Elizabeth Cady Stanton with the purpose of advocating for the abolition of slavery. They successfully petitioned Congress for a constitutional amendment, leading to the ratification of the Thirteenth Amendment.
Step-by-step explanation:
The Women's Loyal League (1863-1865) was formed by Elizabeth Cady Stanton as a political organization with the purpose of advocating for a constitutional amendment abolishing slavery. They petitioned Congress for this amendment, and their efforts proved successful with the ratification of the Thirteenth Amendment. The Women's Loyal League demonstrated the political efficacy of women and paved the way for further advancements in women's rights.