By the 1910s, many preeminent Angelinos were moving to the area around Hancock Park. Despite the fact that much of this region was still farmland, Mary Caswell saw an opportunity for the School to grow, and in 1913 she initiated the construction of a new campus at the present-day location of Third Street and Rossmore Avenue. Marlborough opened its new campus on January 17, 1916, having spent $70,000 on construction in the fledgling neighborhood. According to Grace Wiltshire Drake, the Co-Principal at the time, “Except for a few scattered houses, poppies and other wild flowers were the only occupants of all that vacant ground.”
The day of the move witnessed severe flooding, and, “every piece of furniture for a household of nearly 70 people [boarders and faculty] and the equipment for a school of 150 was carried by hand the some 500 feet to the door of the building” over streets that had turned to mud. “The mud kept trucks from bringing oil for the furnaces, so many tons of coal for heating were wheeled to the house in wheelbarrows on two planks.”
The oldest building on today’s campus, Caswell Hall, was dedicated in 1928, originally featuring bleachers in the back, windows on the south and west sides, and rows of student desks.