CANTON, Ohio  The event was a reunion for people who were never supposed to meet, commemorating an act of charity that succeeded because it happened in secret.

Helen Palm sat in her wheelchair on the stage of the Palace Theater and read her plea for help, the one she wrote in the depths of the Great Depression to an anonymous stranger who called himself B. Virdot.

“I am writing this because I need clothing,” Ms. Palm, 90, read aloud on Friday evening. “And sometimes we run out of food.”

Ms. Palm was one of hundreds who responded to an advertisement that appeared Dec. 17, 1933, in The Canton Repository newspaper. A donor using the pseudonym B. Virdot offered modest cash gifts to families in need. His only request: Letters from the struggling people describing their financial troubles and how they hoped to spend the money. The donor promised to keep letter writers’ identities secret “until the very end.”