The only interstate St. Patrick’s Parade in the U.S. It runs from Illinois into Davenport Iowa. The parade begins at St. Mary’s Church and continues through the downtown area crossing the Mississippi to Davenport, Iowa. – – – The parade begins at 11:30 AM at the corner of 4th Ave and 23rd St in Rock Island and winds its way west thru downtown Rock Island following 4th Ave to 20th St to 3rd Ave to 17th St. to 2nd Ave. to the Centennial Bridge, where it crosses the Mississippi River to Gaines St. in Davenport and then north to 3rd St. and east on 3rd to the River Center.