The 252nd annual New York City St. Patrick's Day Parade made its way up Fifth Avenue on a snowy Saturday, and around two million people watched the thousands of marchers, including bagpipers, step dancers and members of the U.S. armed forces.

Since the holiday falls on a Sunday this year, this largest celebration of Irish pride in the city, stretching from 44th Street, past St. Patrick's Cathedral, to 79th Street, took place the day before.

Spectators wearing green clothing and waving Irish flags came from all parts of the United States, Ireland and other parts of the world. Some even sported shamrocks and leprechaun trappings, and said their Irish pride was the only thing keeping them warm.

"I have the hat and a mustache of a leprechaun, and I have shamrock glasses for St. Patrick's Day," said a parade-goer who was covered in green.

"I like the marching bands, they've been very good," said a parade-goer from Dublin.

One Irish man in the crowd, David Burke, has lived in the United States for 28 years but officially became a naturalized U.S. citizen on Friday. He was proud to join his family to cheer on the parade.

"I have four kids, and I've always been proud of the fact that I've been in this country. It's a country where Americans are not afraid to be proud of their country and even their heritage," Burke said.

The grand marshal this year was Alfred E. Smith IV, the great-grandson of Al Smith, the former New York governor and presidential candidate.

Mayor Michael Bloomberg, Senator Charles Schumer, Irish Prime Minister Enda Kenny and Police Commissioner Ray Kelly were among the dignitaries marching in the parade, and several mayoral hopefuls, including former MTA Chairman Joe Lhota, took advantage of the large crowds to do some campaigning.

However, other politicians boycotted the parade because organizers do not allow LGBT groups to participate.

The luck of the Irish came through for NYPD Officer Jon Vierling and Kelly Collins. Vierling broke away from the line of march to give Collins the surprise of a lifetime, when he dropped to one knee and asked her to marry him.

"I thought was he was working today which is why he couldn't come in," Collins said, immediately after the proposal.

The couple met two years ago on St. Patrick's Day and Vierling said he wanted to keep the proposal Irish.

The day's festivities got underway with a morning Mass at St. Patrick’s Cathedral led by Bishop Dennis Sullivan of Camden, NJ.

Cardinal Edward Egan, the archbishop emeritus of New York, also presided because Cardinal Timothy Dolan is still out of the country for the papal installation. A guest priest from Ireland delivered the homily.

Governor Andrew Cuomo was among the attending worshippers, who packed the pews amid scaffolding for the cathedral's ongoing restoration.

Catholics told NY1 that this St. Patrick's Day is special, coming so soon after the election of Pope Francis.

"It's a beautiful day here at St. Patrick's Cathedral. It's wonderful that we have a new pope, it's wonderful to be here to celebrate," said one attendee.

"We're here today to celebrate the feast of St. Patrick's here in New York City. The reason we do it is our love of what [St.] Patrick gave us. The holy father now took the name of Francis. He'll give the same love as [St.] Francis gave to us, as Patrick gave to us," said another.

Bloomberg Demands Immigration Reform At Pre-Parade Breakfast

Mayor Michael Bloomberg started Saturday at a pre-parade breakfast at Grace Mansion on the Upper East Side, where dignitaries celebrated the contributions the Irish have made to the city.

Bloomberg said one of the challenges the nation faces is to make sure more Irish and other immigrants can keep coming to the United States.

"In Washington, we've just got to have intelligent immigration laws. We are committing national suicide. We need immigrants from all over the world," Bloomberg said. "They are the people who are going to keep challenging us, keep us working hard and create new things and take risks. That's the way America was built. That's why America is here and we've just got to fix it this year."

The mayor also attended another breakfast hosted by the Ireland Chamber of Commerce.