Delaware's Winterthur Museum has purchased a rare 18th-century needlework sampler stitched by an 8-year-old Philadelphia girl who was the daughter of free blacks - ensuring that the important relic remains in local hands.

Samplers were an important part of a girl's formal education in early America, and are seen as a window into the history of women, said Linda Eaton, Winterthur's director of collections. Since most schoolgirls who produced them were white and affluent, a sampler by an educated black girl is considered a major find.

"We're thrilled to get it," said Eaton, who declined to give the purchase price. The sampler was sold to the museum by Amy Finkel of M. Finkel & Daughter, a Philadelphia antiques dealer that received it on consignment from a family in England.

Only a handful of such samplers are known to exist. Winterthur owns two others made by black students, but those date from the mid-19th century.

The sampler was stitched in 1793 by Mary D'Silver, who attended the Bray Associates Negro School, founded by an English abolitionist. It was one three Philadelphia schools open to blacks in the 18th century.

Mary's modest sampler is believed to be one of the oldest in existence by a nonwhite student.

For her sampler, Mary took a stanza from a well-known abolitionist poem by Anna Laetitia Akin Barbauld, "The Mouse's Petition." The poem was an allegory of slavery in which the mouse begs its captor for freedom.

The words are rendered in silk stitches on rough linen fabric in a design about eight by 83/4 inches. In kelly green, the child stitched a simple, irregular geometric vine border enclosing the verse, which she stitched in small, dark-blue letters. For her name, Mary chose a pale pink thread. Unlike some samplers coveted by collectors, there are no images of flowers or trees or houses.

In most cases, Eaton said, teachers assigned the text to students, who might labor for months over a hankerchief-size sampler. She said she suspects that Mary's sampler was intended to be sold to raise money for the school. One word from the poem was changed, making it more of a personal plea by Mary or her teacher.

The tiny needlework was discovered by Finkel, who researched school and church records to unravel Mary's biography.

She was born in Philadelphia and her parents were married in Christ Church. They sometimes spelled their surname DeSilver or Desylvas, suggesting a Portuguese connection.

"That's something I'd like to research," said Eaton. "Who was this family? What was their background?"

She expects to hang the sampler in Winterthur's textile and needlework gallery, along with pieces by two other black students, Rebecca Olivia Parker, who attended the Lombard Street School, and Rachael Anne Lee, who went to school in Baltimore.

More museums are seeking such pieces, said Margaret Hofer, a curator at the New-York Historical Society, which owns one sampler by a free black schoolgirl. "It's way for kids to connect to the past," she explained.

Eaton agreed. Winterthur, founded by collector Henry Francis du Pont, is "a little WASPy, and one of our goals is to establish more diversity in collection."