Presumably named in 1876 to mark the United States Centennial, although the earliest record I found of the street was in 1879. It was christened by Prudent Beaudry (1816-1893) on his Park View tract, either during or shortly after his stint as mayor of Los Angeles. Beaudry (often with his younger brother Victor) owned and developed a lot of the city, and he had a flair for patriotic street names – Bunker Hill, Boston, Custer – although he himself was a French Canadian.
Find it on the map:
