New Yorkers celebrate St. Patrick's Day

NYC firefighters carry U.S. flags in the St. Patrick's Day Parade in New York on Saturday.

NEW YORK (CNN) -- On the day before the holiday, New Yorkers lined Fifth Avenue in unusually warm weather Saturday to watch the St. Patrick's Day Parade, dedicated this year to the victims of September 11.

A moment of silence in remembrance of the terror attacks was observed at 12:30 p.m. ET.

Edward Cardinal Egan, New York's Roman Catholic archbishop, was grand marshal for the 241st annual parade, one of the nation's oldest and largest, honoring Ireland's patron saint.

It featured more than 150,000 participants and about 200 bands. Vehicles, floats and exhibits are not permitted.

Also participating along the two-mile route -- dampened by light, sporadic showers -- were Gov. George Pataki, Mayor Michael Bloomberg and Democratic U.S. Sen. Hillary Rodham Clinton.

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Members of the Irish Lesbian and Gay Organization, whose members have been banned from participating in the march for the past 12 years, were planning to march along the sidewalk.

As is customary, mounted police and the Fighting 69th Infantry pipers led the parade, followed by the grand marshal.

The first official St. Patrick's Day parade in New York was held in 1766 by Irishmen in a military unit recruited to serve in the American colonies. Military units organized the parade until after the War of 1812.

After that, Irish fraternal and beneficial societies began sponsoring the event. About 1851, as individual societies merged under a single grand marshal, the size of the parade grew.

Sponsors and participants include the Ancient Order of Hibernians, the 30 Irish county societies, and various Emerald, Irish-language and Irish nationalist societies.