O'Neill Park was dedicated on June 18, 1950, as a memorial to Richard O'Neill, a California pioneer of 1850, his wife Alice O'Neill, Jerome O'Neill, and Richard O'Neill Jr. At El Trabuco - Mission Viejo in 1769, Captain Gaspar de Portola, Padre Crespi, and soldiers traveling north to Monterey Bay camped on the banks of a stream named El Trabuco for the lost blunderbuss. In 1776, Padre Junipero Serra was halted there by hostile Indians as he journeyed to Mission San Juan Capistrano.