Casarez was born in 1971 in Philadelphia. By the time she was a teenager, AIDS was ravaging the LGBT community in Philadelphia and around the world.
John Anderies, director of the archives at the William Way LGBT Community Center, says as a student at West Chester University, and later at the University of Pennsylvania, Casarez worked for the homeless and for people with HIV and AIDS.
She fought for social justice through the Gay and Lesbian Latino AIDS Education Initiative, and she joined the city administration to push for LGBT rights. She ultimately was named director of LGBT Affairs for the city of Philadelphia.
"She was really quite spectacular," Anderies said. "You know, everybody that I've talked to said she was really a force of nature and could really marshal people and inspire them."
Anderies says Casarez also worked hard to earn Philadelphia the highest standing with the Human Rights Campaign, the nation's largest civil rights organization working to achieve LGBT equality.
"During her tenure in city hall, she was really instrumental in helping to make that case to HRC, to make Philadelphia be one of the top cities," he said.
Casarez died in 2014 after fighting breast cancer for five years. Anderies says the historical plaque will most likely be placed at City Hall, but the application process is still underway.
"That is certainly, for many people, the place that they think of when they think of Gloria. She was responsible for the first raising of the rainbow flag at City Hall. When she died, the rainbow flag was lowered to half mast there."
Last year, Project HOME opened the Gloria Casarez Residence, which provides affordable homes for homeless young adults in the LGBT community.