Pope Benedict has proclaimed four new saints at a canonization ceremony in Saint Peter's Square. They included an American 19th century nun, a Mexican bishop and two Italian founders of religious orders. 

In his homily, Pope Benedict said four new saints are now being proposed to the veneration of the universal church. He said they would be remembered forever. The new saints include two Italians Filippo Smaldone and Rosa Venerini, who founded religious orders, and two foreigners.

Many Mexicans turned out in Saint Peter's Square Sunday for the canonization ceremony, which included one of their own. Bishop Rafael Guizar y Valencia risked his life to assist the wounded during the Mexican revolution.

The Pope said Rafael Guizar y Valencia was called the bishop of the poor because of the heroic way in which he lived charity.

Americans were also present to celebrate a French-born nun who endured harsh conditions in what was American frontier land at the start of the 19th century and pursued her dream of establishing Catholic education for pioneers.

Mother Theodore Guerin established a college for women in the midwestern state of Indiana. Pope Benedict said she overcame many challenges.

Members of Guerin's order and hundreds of students from St. Mary-of-the-Woods College and their families traveled to Rome for the canonization ceremony. Among them was Sandy Callaghan, from Michigan who graduated from the college in 1961.

"I think it's wonderful, absolutely marvelous, just phenomenal," she said. "It's just something like a dream come true. I mean, they've been working on it for so long and I was in college when they were proceeding with the process and just to see if finalized, that's why we're here."

Sunday's canonization ceremony was Pope Benedict's first in nearly a year. While his predecessor celebrated both canonization and beatifications regularly doing the year, soon after his election Benedict decided that beatifications would be held in the country where the saint originates from or worked.