Doris Polsky, 90, helped integrate Mount Airy

Doris Polsky, 90, a precocious mathematician who helped integrate Mount Airy, died Wednesday, June 3, in her home at Cresheimbrook Condominium.

Along with her twin sister, she was recruited out of the Philadelphia High School for Girls to work on Army ballistics research during World War II. Together, they also helped found the Allens Lane Art Center and West Mount Airy Neighbors.

As owners of Twin Realty, they helped stanch white flight in Northwest Philadelphia during the 1960s, thwarting banks' redlining practices and selling to people of all colors, creeds, and sexual orientations.

"When interviewing the two sisters, I was taken by how humble they were about their amazing accomplishments," said LeAnn Erickson, who featured them in the 2010 film Top Secret Rosies: The Female Computers of World War II. "It was just the way they lived their lives."

Mrs. Polsky was born Doris Blumberg in Grays Ferry. She and her sister, Shirley Blumberg Melvin, were children of Esther and Jacob Blumberg, who owned a real estate brokerage.

Mrs. Polsky and her twin graduated from Girls High and were scouted by the military in 1942 to help produce special ballistics tables at a research lab at the University of Pennsylvania. They soon began working six days a week producing materials that helped the Army make significant gains in the European and Pacific theaters.

The Army asked them to program the differential analyzer, a large mechanical calculator that in 15 minutes could complete the mathematics that had taken one person 40 hours, Erickson said.

After the war ended, Mrs. Polsky married Temple University law professor Samuel Polsky, whom she had met on a blind date. They had two sons, Scott and Steven, and three daughters, Joan, Lisa, and Ellen.

"I feel really blessed to have grown up with these incredible and highly educated parents who taught us early on that everyone matters and all people need to be treated equally," said Ellen Polsky, who works at a community center that helps immigrants and refugees.

Mrs. Polsky opened Twin Realty in 1965 in Germantown. The company hired only women in an effort to combat sexism. It established a group day-care so mothers could work.

In a 2009 interview, Ms. Polsky said she was able to stop white flight and prevent blockbusting in her neighborhood by finding like-minded people whom they would approach and ask to throw welcoming parties for their new black neighbors. Over time their method proved successful.

"There were black and white people living in Mount Airy in Philadelphia and the Realtors were playing games . . . and according to sources they persuaded white people not to leave and vice versa," said Dorothy Kapenstein, a Girls High 1946 alumna and the director of the Girls High alumni club. Kapenstein researched the twins' lives and was in charge of the installation ceremony when they were inducted to the school's hall of fame in 2012.

Mrs. Polsky and her sister's humanitarian and civic efforts helped Mount Airy earn recognition as one of the nation's best-integrated communities by the U.S. Department of Housing and Urban Development.

"We owe Mrs. Polsky a debt of gratitude for creating a diverse neighborhood and combating white flight," said Karima Bouchenafa executive director of West Mount Airy Neighbors.

Mrs. Polsky and her sister's work to integrate their neighborhood was recognized in 2004 by the Philadelphia Commission on Human Relations.

Mrs. Polsky and her sister retired from Twin Realty at age 60. Her husband had died in 1975. In 2005, Mrs. Polsky was the recipient of a lifetime achievement award from the art center. Four years later, she received the Senate of Pennsylvania Award in recognition of contributions to her community.

Melvin died at age 84 in 2009.

In addition to her children, she is survived by 12 grandchildren and one great-grandchild.

There were no public funeral arrangements, at her request.