A Jewish federation says it organized Thursday's rally to "restore a sense of security and peace to our community."
Over 100 headstones were recently discovered damaged at Mount Carmel Cemetery. Police haven't made an arrest or determined a motive.
Jewish community centers and schools in at least a dozen states were also targets of bomb threats this past week, the fifth wave since January.
At the rally, Democratic Gov. Tom Wolf called the cemetery vandalism "the desecration of the values we all hold dear" and the bomb scares "threats against each and every one of us and our common humanity."
The latest incident came when a Jewish cemetery in Rochester, New York, had at least five headstones toppled, according to New York and Jewish media reports on Thursday evening.