Superb portrait of 19th-century black women

We Are Your Sisters: Black Women in the Nineteenth Century, edited by Dorothy Sterling. New York: W. W. Norton. 537 pp. $22.50.

By juxtaposing letters, notes, and childhood memories of slaves and free women, this comprehensive anthology goes a long way toward telling the story of the black woman in the 19th century.

The images are poignant: milk placed in a wooden bowl on the floor; children eating from oyster shells; young women learning to be ''house women'' by shooing flies from the dinner table, peeling potatoes, bringing milk from the well; the awful consequences when a hungry slave would be caught stealing a sugar cube. These scenes and the others which begin this well-edited book read better than fiction and have the vividness of poetry.

The accompanying photographs and etchings show their subjects dressed as men or stripped to the waist, armed with brooms or seated defiantly with grim, unsmiling faces or standing behind their seated husbands. There are no ''mammies'' here.

This is a world in which white men can put blacks on the auction block at any time. The book records the bitter memories of young sisters being given away, abused, and dying, of marriages broken up when a speculator comes and takes a husband.

Some extraordinary individuals emerge from this narrative. One of them is Eleanor Eldridge, who bound herself to a family for 17 years, working for 25 cents a week. With her meager savings she bought land, only to be swindled out of it. Then she wrote her autobiography and peddled it from New England to Philadelphia to earn money to buy back her land. Another is poet Frances Harper, who donated the money that came from her poetry to the underground railroad.

Most remarkable are the ''schoolmarms,'' who went to the South to teach in churches and homes and eventually started schools. ''I think it is our duty as a people to spend our lives in trying to elevate our own race,'' said one of them.

Noble and romantic as they sound, these were actually realistic women who knew that no one else - no Peace Corps, no social organization - would do it for them. Slavery had made them tough - tough enough to travel North or West, not behind, but beside their men. In fact, they often led the way.

In her epilogue, Ms. Sterling presents four women, both free and slaves, who speak so intelligently and ambitiously in their diaries that they reawaken our interest the journal as a literary form.

Wrought with an honesty that transcends mere trendiness, Sterling's book somehow becomes more than the sum of the documents, by both known and anonymous women, from which it draws. Here, Harriet Tubman, Sojourner Truth, and Emma Brown assume equal importance as figures in a broad landscape and form a picture of the past on their own terms.