The Library of Congress has acquired the remaining records of the National Woman’s Party, adding substantially to its already sizable holdings relating to one of the major organizations that advocated for women’s suffrage.

The donation unites more than 300,000 documents, photographs, letters, broadsides, scrapbooks and other items relating to the party with another 200,000 items previously acquired by the library. The new materials relate to all stages of the party’s history, from its founders’ earlier involvement in feminist activism to the fight over the 19th Amendment to its decades of advocacy for the Equal Rights Amendment.

“American history is not complete without women’s history,” Carla Hayden, the librarian of Congress, said in a statement about the acquisition, which coincides with the women’s suffrage centennial. “We will be proud to make this historic collection of the National Woman’s Party available to the nation.”

The National Woman’s Party was founded in 1916 by Alice Paul and Lucy Burns, who advocated for increased militancy in the suffrage battle. In early 1917, it began organizing the first regular pickets of the White House, in which protesters, known as the Silent Sentinels, sharply challenged President Woodrow Wilson to support a federal amendment giving women the vote.

After initially tolerating the protests, the government began arresting and jailing suffragists, who were denied the status of political prisoners. In protest, some went on hunger strikes, which resulted in brutal force feedings.

The NWP’s confrontational tactics put it at sharp odds with the more mainstream National American Woman Suffrage Association (NAWSA), which at the time was focused on winning the vote state by state. And the rivalry between the two groups also influenced the archival collecting of the movement.

In 1920, after the 19th amendment was adopted, NAWSA donated some artifacts to the Smithsonian Institution (which is separate from the library), but only on the condition that any exhibition on the suffrage movement not mention the National Woman’s Party or Paul.