Yes Warhoover. I've lived in the US for 30 years now so know what you mean.
In Australia, there was a simultaneous Catholic Mass, Anglican & Presbyterian services. Then Assembling at the Catholic Cathedral began an "Orange & Green" parade together (Catholics & Protestants) Pipers, drummers, flutes etc. Various Irish flavorded charity groups, kids etc. Led by a banner (with orange & Green ribbons) depicting St. Patrick in his Bishop's finery. At the end of the parade rode together in an open car. the Two Bishops & the Moderator of the three Churches.
Then a BBQ/Irish Faire at the park . Some drinking, but moderate, as it was a family day. Lots of dancing, games etc. We usually held it on the nearest Saturday to the 17th.
Here they swill down the booze & drunkenly confess on the six O'clock news that they don't have a clue who St. Patrick is - then everyone grins drunkenly & cheers!!! Oi Veh! Not very uplifting. Watch out, Sts, Andrew & David will be next.