The first Rathayatra festival in the western world was celebrated in San Francisco on July 9, 1967 (see poster here). A flatbed truck was used to carry the Deities through the Haight-Ashbury district to the sea. The second Rathayatra festival occurred the following year on June 30, 1968 (see poster here). This video features Jayananda Prabhu (first seen at 0:19) helping to build the carts and the procession to the beach. Also includes a beautiful soundtrack of previously unreleased bhajans by Srila Prabhupada.
(Click here for more information about Jayananda.)