The Main Street Branch Library is one of four branch libraries for the City of Huntington Beach. The library's site-cast, concrete tilt-up construction during Southern California's post-World War II building boom was considered novel at the time. Triangle Park was informally used for recreation beginning in 1912, three years after the incorporation of Huntington Beach in 1909. The Canary Island Palm Trees lining the park were planted between 1924 to 1925. The Library and Triangle Park were listed on the National Register of Historic Places in 2013.
In 1917, the Huntington Beach Company officially deeded land blocks number 405
and number 505 to the Huntington Beach Township, specifying public park uses. The land had been used prior to this for community recreation. Triangle Park was associated with a baseball field from 1912 to the early 1930s, a tent city for oil workers from 1921 to 1923, croquet and tennis in the 1920s through 1930s, the game of horseshoes circa 1931, and a putting green from 1927 to circa 1950. The park land was temporarily used
for tents to house the constant flow of new residents upon the discovery of oil in 1920. A 1921 city report notes a lease contract was signed with R.E. Wright who constructed small beaverboard houses on the park land. Wright rented the temporary shacks in what was called Bungalet Court for $30 to $35 a month. The area became known as 'Cardboard Alley'.Triangle Park became part of a larger civic center
complex in 1922, including a city hall, Memorial Hall, and the Horseshoe Club in 1931. In February 1925, the Township's board of trustees discussed with considerable interest a suggestion to use the land for a recreation park, suggesting tennis, croquet,
and handball courts as being a very desirable form of amusement. By the late 1920s, the community added a lighted baseball diamond, grandstand,
and the horseshoe grounds. During World War II, the American Red Cross set up headquarters in the
Horseshoe Club building, providing first aid and rolling bandages for
the war effort. The U.S. Army used the clubhouse at nearby Lake Park, as well as the Huntington Beach pier for submarine watch during this time. Construction began on the 9,034-square-foot Main Street Branch Library in 1949. It was designed in what was known as the International Style, more recently called Mid Century Modern. The library opened in 1951 and the town's 1914 Carnegie Library at 8th and Walnut streets was closed and demolished.The Main Street Branch Library held a collection of between 40,000 to
50,000 books and served as the main public library for the community
from 1951 up until 1975. A handcrafted grandfather clock in the library's main room was donated by the senior class of Huntington Beach High School in 1914.The Main Street Branch Library remains an active branch library for Huntington Beach, with large reading room, a computer room, children's book section and children's story times.