article_snippet: The day itself is not until Tuesday - but many dressed up in green as processions began to take place.
article_snippet: Spectators who had traveled from all parts of the country gathered on the banks to watch the tradition unfold .
article_snippet: Police will are also preparing for the festivities, with forces around the country putting on extra officers and increasing DUI checkpoints.
article_snippet: It is the fourth most popular drinking day of the year - behind New Year's Eve, Christmas and the Fourth of July.
article_snippet: Crowds gather along the parade route outside The Gateway Salt Lake City, Utah .
article_snippet: Spectators line the streets in Lincoln, Nebraska, during the build up to the procession .
article_snippet: A woman walks by rows of steel barricades set up for Saturday's street party in the Pittsburgh's Market Square .
article_snippet: Workers unload a truckload of portable toilets  in the Pittsburgh in time for the celebrations .