Mary Benn Johnson, 99, who worked in libraries for more than 50 years, died Tuesday at Waverly Heights, a retirement community in Gladwyne.

A native of Cambridge, Mass., Mrs. Johnson graduated from Maryville College in Tennessee and met her future husband, Julian Johnson, while singing in the college choir. She earned a bachelor's degree in library science from Drexel Institute of Technology, now Drexel University, in 1931 and then was a librarian for 14 years with the School District of Philadelphia.

After she and her husband and daughter moved to Gladwyne in 1957, she was a volunteer with the Gladwyne Free Library and served on its board.

In 1986, she and her husband were among the original residents of Waverly Heights, where she organized a library in the Manor House building and later helped establish a second library in the Blair building.

She regularly drove to Barnes & Noble to buy new books for the libraries, said her daughter, Joan McHugh, who is also a librarian. When she stopped driving she got others to chauffeur her, her daughter said. She was Waverly Heights librarian until 2004.

Mrs. Johnson was a member of the PEO Sisterhood, which promotes education for women. She enjoyed traveling, especially to England, music, and gardening. She loved animals and owned dogs for most of her life, her daughter said, but in recent years had a cat, Waverly.

In addition to her daughter, Mrs. Johnson is survived by nieces and nephews. Her husband died in 1987.

A memorial service was held Saturday at Ardmore Presbyterian Church, 5 W. Montgomery Ave., Ardmore.