The collection contains six commemorative, stamped and canceled envelopes celebrating the California Republic sesquicentennial
anniversary in 1996. Envelopes include: Bear Flag Sequicentennial Committee, with Bear Flag raising ceremony in the Sonoma
Plaza illustration; Mariano Guadelupe Vallejo, with Lachryma Montis (Vallejo's Sonoma home) illustration; Sum-Yet-Ho (Solano),
Chief of Suysunes tribe; Bear Flag creation at Sonoma Barracks; John C. Frémont and the "Bear Flag" Battalion, June 14, 1846;
and raising of the 28-star flag of the United States at the Sonoma Plaza. Stanps were canceled June 14, 1996 at the Sonoma
Plaza Station, Sonoma, California.