San Francisco has long been host to big St. Patrick's Day celebrations though the parade's gotten a bit smaller in recent years the first of which was held in 1850's, during the Gold Rush. The city's first celebration took place in 1851, when there was a party at Hayes Valley Park followed by a Shamrock Ball at a nearby bar. The first parade is said to have taken place a couple of years later, in 1853 — it was a lengthy affair also followed by a Ball.
These early parades kept growing over the first decade, thanks in part to Colonel Patrick Connor, whose troops were stationed in Stockton during the Civil War. According to the Hibernian Society of Utah (where Connor's mostly-Irish regiment was from), Governor Downey invited Connor to lead the annual parade one year:
Conner brought 20 of his officers and the regimental band to the parade. The San Francisco papers gave great play to the participation of Connor's troops. The parade also included many Irish organizations: the Irish American Benevolent Society, St. Patrick's Brotherhood, and the Sons of Erin. After the grand parade, a high mass was celebrated at St. Mary's Cathedral. In the evening there was a grand ball at Hayes Park with speeches, orations, recitations and parties that went on until the wee hours of the morning. The festivities of that St. Patrick's Day, 1862 in San Francisco, would be the model for St. Patrick's Day celebrations.
Pieces of its history are still part of the parade today, and Diarmuid Philpott, former Deputy Chief of the SFPD and past president of the United Irish Societies of San Francisco (they help coordinate the parade) has explained that the route "passes by the names of some of San Francisco’s most prized Irishmen... Particularly O'Farrell Street, which is called after Jasper O’Farrell, who was an Irish engineer, surveyor, born in Dublin, and who laid out San Francisco as we know it today."
As third generation Irish-American Bay Area native Mary McCloy tells it, some early Irish immigrants who made it west during the Gold Rush got land grants from the Mexican government so many in Marin County, in fact, that it was nicknamed Little Ireland at the time. In 1852, San Francisco had an Irish population of 4,200 which grew in the next thirty years to 30,000, representing well over a third of the city's population. They helped elect the first Irish-born mayor in the United States, in fact, Frank McCoppin, in 1867. That history is reflected today in the dozens of Irish bars and pubs all over town and the many Irish organizations who march in the parade.
These days the parade takes place on the Saturday before St. Patrick's Day, and you can see photos from last Saturday's 165th annual parade here at the Examiner. The route is the same as most large parades, either for the Giants or Gay Pride, starting at the foot of Market and turning up McAllister to Civic Center. This year's event celebrated the 100th anniversary of the 1916 Easter Rising in Ireland, which lasted six days and ultimately lead to the establishment of the Sinn Féin party and the election of 73 Irish republicans to the British Parliament two years later, who pushed for Irish independence.
ABC 7 has some video of this year's (fairly windy) parade.
Thursday, March 17, on actual St. Patrick's Day, there will still be plenty of parties at Irish pubs around town many of which we included in this list of the best places to eat Irish food in SF.
Downtown, you'll find an especially lively celebration at The Irish Bank (10 Mark Lane) downtown starting at 2 p.m. and going into the evening, featuring live music Paddys Orchestra from 2 p.m. to 5 p.m., The Shams from 5 p.m. to 8 p.m., and DJ Marc Van Brabant from 8 p.m. to midnight.