The National Women's Party (NWP) will celebrate Women's Equality Day tomorrow with a garden party at Sewall-Belmont House, the party's Capitol Hill headquarters since 1929 and a monument to the struggle for women's suffrage.

The organization will commemorate this 63rd anniversary of the passage of the 19th Amendment, granting women the right to vote, at the mansion, 144 Constitution Ave. NE, where banners, busts, photographs and documents commemorate the suffrage struggle. From the mansion, the NWP also continues its effort to pass the Equal Rights Amendment.

The oldest house on Capitol Hill, the Sewall-Belmont House was to be demolished to make way for the Hart Senate Office Building, which looms next door, but was preserved by efforts of the party.

"First we got it on the National Register of Historic Places and then we had it declared a National Landmark, with the help of Lady Bird Johnson," said Elizabeth Chittick, president of the party since 1972.

Named for an earlier owner, Robert Sewall, and Alva Belmont, an NWP member and benefactor, the house is maintained under a cooperative agreement between the party and the National Park Service.

In the NWP office, staffers use a desk once owned by Susan B. Anthony and a chair that belonged to Elizabeth Cady Stanton.

Busts of Anthony and Stanton adorn the historic building's Hall of Statues along with one of Lucretia Mott, the Quaker minister, homemaker and abolitionist who, with Stanton, organized the first women's rights convention in Seneca Falls, N.Y., in 1848.

Alice Paul, who co-founded the NWP in 1913, is also honored by a bust. A Quaker from New Jersey, Paul was imprisoned during more militant suffrage efforts by women in England and brought some of their tactics to the United States in 1910. Working outside the mainstream National American Woman Suffrage Association, which favored lobbying Congress and seeking grass-roots support in the states, Paul and her party adopted confrontational methods.

For more than six years they sponsored parades and demonstrations, picketed appearances by President Woodrow Wilson and unfurled a huge banner during a congressional address.

"We demand an amendment to the United States Constitution enfranchising women," reads the "Great Demand Banner," carried in NWP demonstrations from 1913 to 1919. It now hangs above the stairway at Sewall-Belmont.

Suffragists were arrested for "obstructing traffic" on the White House sidewalks and many were jailed. In prison, some of the women went on hunger strikes and were force-fed. A marker now stands near Lorton Reformatory, the former site of the Occoquan Workhouse, where most of the suffragists were jailed.

Such demonstrations were "colorful pageantry," Chittick maintains. "I don't know why people keep calling Alice Paul militant; she was peaceful. As a Quaker, she was a peace advocate; she was not militant."

While attending a 1923 NWP gathering in Seneca Falls to celebrate the 75th anniversary of the 1848 convention, Paul wrote the Equal Rights Amendment, reasoning that the 19th Amendment had fulfilled just one of the 12 original Seneca Falls resolutions.

At her death in 1977, Paul was still lobbying state legislatures to ratify the amendment, as her successors do today.