PHOTOS: Going green in NYC

The annual St. Patrick's Day Parade brings together hundreds of thousands of marchers in one of the largest American celebrations of Irish heritage. The first parade took place in New York City in 1762. With an increase of Irish immigrants coming into the United States, St. Patrick’s Day quickly became a widespread holiday. Approximately 150,000 people participate in the New York City parade each year, and around 2 million people come out to watch. (Yahoo News)