Ince stayed just long enough to complete a few stages and an administration building, then sold his shares to his partners and moved his operation down the street to what would someday become The Culver Studios. By 1918, Triangle Studios was up for sale, attracting the attention of the ambitious movie producer Samuel Goldwyn.

Goldwyn took over the studio, added a few stages and buildings, then was ousted before the Metro-Goldwyn-Mayer merger took place in 1924, the same year Columbia Pictures was born in Hollywood. MGM rapidly grew to six working studio lots, of over 180 acres by the end of the 1930's, under the management of Russian immigrant Louis B. Mayer. The main lot resembled a city within a city with its own police and fire departments, telegraph and post office, and a 16,000-gallon water tower. All the backlot amenities necessary for moviemaking were on site: sawmill, electrical, paint and lock shops, wardrobe, make-up, property, lighting and camera departments. By the late 1920's, the glass-walled stages, built to maximize the natural light required for early film technology, were replaced by sound stages (28 during MGM’s tenure). Stage #15 was the largest in the world. Another stage featured a huge water tank used for filming scenes underwater.

Louis B. Mayer was close to his brilliant head of production, Irving Thalberg, who had been placed in charge of the studio at the age of 24. In its heyday, MGM released 50 films a year with a payroll of over 5,000 employees.