On the national level, the combined efforts of NAWSA and the National Woman’s Party finally drew a response from President Wilson. In January 1918, Wilson met with Democratic congressmen and together they pledged to support women’s suffrage. Wilson was aware that other countries such as Great Britain in 1918 were passing suffrage legislation. He decided to wait until the end of the war, however, linking the right to vote with women’s contribution to the war effort in his rhetoric, stating that “women have been the partners of men in war. Shall we admit them to only a partnership of sacrifice and suffering and toil and not to a partnership of privilege or right?” In January 1918, the House of Representatives voted in favor of the Susan B. Anthony Amendment. The suffragists threw themselves into lobbying New Jersey’s senators, but in October 1918, the bill was defeated by two votes.

Both NAWSA and the NWP worked to support pro-suffrage candidates in the 1918 elections. In New Jersey, Republican Senator David Baird of Camden was one of the two who had voted against the amendment in October. Baird had been appointed to fill the unexpired term of the late Senator William Hughes who was pro-suffrage. Baird had pledged to vote against the suffrage amendment even though it was endorsed in the Republican party platform. Led by scientist Mary Mitchell Moore (b. 1892), the president of the New Brunswick Equal Suffrage League and the first woman to earn a doctoral degree at Rutgers, local suffragists campaigned against Baird, holding a mass meeting in downtown New Brunswick on October 29, 1918. The meeting featured Florence B. Hilles (1865–1954), an ambassador’s daughter and an officer of the National Woman’s Party, who spoke from a car decorated in purple, white, and gold. Their efforts were largely successful: New Jersey elected two pro-suffrage senators, Walter Edge and Joseph Frelinghuysen to the 66th Congress, which passed the Susan B. Anthony Amendment on June 4, 1919.

After the passage of the amendment, NJWSA mobilized for the ratification fight. NJWSA established the New Jersey Suffrage Ratification Committee coalition with other major women’s organizations including the New Jersey Federation of Women’s Clubs (which had endorsed suffrage in 1917), the Woman’s Christian Temperance Union, teachers and nurses associations, and labor unions. Representatives were chosen from nineteen counties and Lilian Feickert was elected president. The New Jersey Woman’s Party was not part of the coalition but lobbied for women’s suffrage on its own. In late June 1919, Middlesex County women met in New Brunswick at the newly founded state women’s college, and organized for the purpose of assisting more efficiently in the coming campaign. Sarah DeMott Stevens of New Brunswick was elected campaign chairman, while other officers included Helen Norris Prickett (1871–1942) of Metuchen, Mabel Haywood (1885–1973) of Perth Amboy, Bertha Hall Jennings (b. 1877) of Stelton, and teachers Susie V. Crabiel (1892–1980) of Milltown and Chrissie Bartlett of New Brunswick. The first Middlesex County meeting was planned for the following month at the home of Sarah Selover in South River. At the end of the meeting, Dean Mabel Smith Douglass (1874–1933) gave a short presentation about the new college, which had opened in September 1918.

The immediate need was to support pro-suffrage candidates for the 1919 state legislative elections. In a major departure, the Democratic party came out for ratification with the support of Hudson County Democrats led by a new power broker, Frank Hague of Jersey City. The Republicans were more mixed, although Senator William B. Mackay of Hackensack agreed to be the sponsor of the bill. In January 2020, the Ratification Committee opened a campaign headquarters in Trenton, and at the end of the month, held “the most spectacular suffrage mass meeting ever held in New Jersey” at the Crescent Temple in Trenton, where each county chair presented her part of a petition of 140,000. When the 1920 legislative session began, Mackay introduced the resolution, which passed 18 to 2. In the assembly, Henry G. Hershfield of Passaic shepherded the measure through a grueling procedural struggle. After a five-hour debate, on February 10, 1920, New Jersey became the twenty-ninth state to ratify the Nineteenth Amendment. Despite resistance from the Deep South, the Susan B. Anthony Amendment was ratified when Tennessee became the last state to vote on August 18, 1920.