Alva Erskine Smith Vanderbilt Belmont was a wealthy socialite who was also a committed suffragist. She used her fortune to support efforts to win the vote for women. She was the president and primary benefactor of the National Woman's Party (NWP) founded by Alice Paul. Because of her support, the NWP was able to launch ambitious campaigns to pass the 19th Amendment, including protests at the White House which led to arrests and imprisonment for hundreds of women.
Belmont initially supported suffrage organizations focused on state voting rights like the National American Woman Suffrage Association (NAWSA). She witnessed a rally in London organized by he Women's Social and Political Union (WSPU), the militant suffrage organization founded by Emmeline Pankhurst and her daughters, Inspired by the suffragettes' actions and intensity, Belmont began to favor more confrontational tactics used to secure a federal amendment enfranchising women. She joined the executive committee of the Congressional Union for Woman Suffrage (CU), formed after Lucy Burns and Alice Paul broke away from NAWSA in 1914 over personal and philosophical differences. The name of the organization changed to the National Woman's Party (NWP) in 1916.
With Belmont's attention came her bountiful resources. She played a significant role in the work of the CU and NWP, She provided money to finance their ambitious campaigns. Her social prominence also won both publicity and respectibility for their efforts, which many considered radical and militant. She often hosted suffrage gatherings at her opulant summer mansion in Newport, Rhode Island known as "Marble House." The house is now on the National Register of Historic Places.
After the ratification of the 19th Amendment in August 1920, Alva Belmont continued to support the work of the National Woman's Party in the ongoing struggle for women's social, political, and economic equality. Because of her generous patronage, the NWP was able to purchase a permanent headquarters on Capitol Hill. Initially, the NWP bought the Old Brick Capitol, a historic building on First Street, NE. The federal government seized that building through eminent domain and demolished it to build the Supreme Court. With Alva's continued support, the NWP then purchased the grand house at 144 B Street, NE (now Constitution Avenue) which they named the Alva Belmont House in her honor. In 2016, the headquarters was declared a National Monument and became a National Park Service site as the Belmont-Paul Women's Equality National Monument.