NEW YORK (AP) - People all over the world are celebrating St. Patrick's Day today. The day is named after St. Patrick, who introduced Christianity to Ireland about 1,500 years ago and became the country's patron saint.

Check out the photo gallery at left for pictures of celebrations from around the world.

Cedar Rapids
Thousands will descend on downtown Cedar Rapids today for the 35th annual SaPaDaPaSo parade for St. Patrick's Day.

The parade starts at 1 p.m., and it looks like the weather will cooperate this year.

SaPaDaPaSo actually stands for Saint Patrick's Day Parade Society.

The parade will travel on the traditional downtown route along Second and Third avenues SE. It will start on Sixth Street downtown, wind down Second Avenue to Second Street and go back up Third Avenue, ending at Fifth Street.

This route allows plenty of space for parade goers to watch it go by. And if you can't make it to the actual parade, you can watch it on local 9.2 KCRG and right here on KCRG.com.

New York
Paradegoers in kilts and green body paint came to New York City from all over the nation on Wednesday to join what organizers bill as the world's oldest and largest St. Patrick's Day parade.

As many as a quarter-million marchers were heading up Manhattan's Fifth Avenue, and crowds gathered along parade routes in cities around the country to mark the emerald-hued holiday.

With the sun shining and temperatures in the 60s, a large turnout was expected in New York City.

Parade participants on Wednesday included the "Fighting 69th," a New York National Guard unit whose history stretches to the U.S. Civil War when immigrants made up the so-called "Irish Brigade" of the Union Army.

Gov. David Paterson and Mayor Michael Bloomberg attended Mass at St. Patrick's Cathedral before the parade.

Representatives of lesbian, gay, bisexual and transgender groups were not allowed to participate in the march — at least, not under their own banner.
Members of the Ancient Order of Hibernians, who run the nation's biggest St. Patrick's Day celebration, say they may invite whomever they please.
Bloomberg favors inclusion, but still planned to participate.

Savannah
In Savannah, Ga., organizers put up crowd control barricades for the first time in preparation for big crowds at the city's 186th St. Patrick's Day parade.

Columbus
Columbus, Ohio, was expecting a record 121 marching groups including Irish clubs, police and fire departments and pipe and drum bands.

Dublin
In Ireland, more than a half-million people lined the two-mile route of the flagship Dublin parade, which has a theme this year that celebrates the global spread of the Irish.

Boston
In Boston, city and state government offices were largely shuttered, as locals marked Evacuation Day. It commemorates a British retreat from Boston in March 1776. But because it coincides with St. Patrick's Day, it has become a controversial holiday amid the down economy as private sector employees continue trudge to their jobs.

Legislative Republicans failed Tuesday in their latest effort to repeal the holiday, a move that is supported by Democratic Gov. Deval Patrick.

While the Black Rose and other Boston Irish pubs were open as early as 6 a.m., the city was not holding a parade. That took place Sunday in South Boston, but the crowds were sharply off amid a strong rainstorm that lashed the region.

Washington D.C.
It was expected to be a mix of lighthearted cheer and serious politics at the White House, where President Barack Obama was meeting with Ireland's Prime Minister Brian Cowen.

The White House event was also expected to draw Northern Ireland leaders, First Minister Peter Robinson and Deputy First Minister Martin McGuinness.