Final answer:
The author of the 1870 pamphlet would support the Suffrage Movement, emphasizing women's need for legal recognition and the right to vote to address societal issues.
Step-by-step explanation:
Based on the 1870 pamphlet passage that emphasizes women needing the ability to "convince the other sex and particularly law-makers of the justice of her claims for herself as woman," the author would support the Suffrage Movement.
The passage references women's quest to be a 'power' in society and the struggle to achieve legal recognition and equal rights, particularly in convincing lawmakers.
This aligns with the historical context of the Suffrage Movement, which sought to secure women the right to vote, empowering them to demolish societal vices and oppression through legislative influence.