WASHINGTON – The nation’s capital was swarming with women wearing crimson and cream, as one of the country’s largest African-American sororities gathered to celebrate 100 years of sisterhood.

More than 12,000 members of Delta Sigma Theta Sorority Inc. convened to mark the organization’s centennial this weekend with activities including community service, a rededication and an awards ceremony.

Members from across the country participated in 22 projects throughout the District of Columbia on Friday in honor of their 22 founders.

The sorority was also using the weekend to thank those who have collaborated with them in service. They held a rededication luncheon and gala on Saturday that was emceed by actors Tim Reid and Daphne Maxwell Reid.

The gala honored members, organizations and individuals who represent the sorority’s mantra.

The festivities culminated on Sunday, the sorority’s actual centennial, with a black-tie dinner with guest honoree General Electric CEO Jeffrey R. Immelt.

The weekend celebration is a part of series of centennial year events for the sorority. In March, the Deltas will re-enact the Woman Suffrage Parade of 1913, in which their founders participated. The sorority will gather in Washington again in July for its national convention.

Delta Sigma Theta Sorority Inc. was founded on Jan. 13, 1913, on the campus of Howard University. The sorority has more than 250,000 members and more than 900 chapters.

Members have included activists Mary McLeod Bethune and Dorothy Height and congresswomen Shirley Chisholm and Barbara Jordan. Other notable members include: poet Nikki Giovanni, journalists Gwen Ifill and Soledad O’ Brien, singers Aretha Franklin, Lena Horne, Leontyne Price and Roberta Flack, and actresses Cicely Tyson and Ruby Dee.