It was one of a number of events taking place around the country this week to preserve and strengthen the government plan.
Unless Congress acts, the program's combined retirement and disability trust funds are expected to run out of money in 2037
"We're celebrating the birthday; we must want it to have many, many more opportunities but we have to make that happen by getting the word out that it is at risk that there is a challenge to it," Pelosi said.
Many Democrats oppose a cut in benefits to reduce costs and some will not accept an increase in the retirement age. Republicans say higher Social Security taxes are out of the question even for the wealthy.
