Final answer:
The National American Woman Suffrage Association (NAWSA) rectified old differences by merging two groups and adopting new strategies such as linking suffrage to traditional gender roles. They also adapted their approach during World War I by throwing support towards the war effort.
Step-by-step explanation:
The National American Woman Suffrage Association (NAWSA) rectified old differences by merging two groups, the National Woman Suffrage Association (NWSA) and the American Woman Suffrage Association (AWS), in 1890. This merger allowed NAWSA to gain membership and momentum. Additionally, NAWSA adopted new strategies, such as linking suffrage to traditional gender roles, which led to some gains for the movement, particularly in the West. They also adapted their approach during World War I by throwing support towards the war effort, which helped to end opposition to women's suffrage.