These men were: Leland Stanford (1824–1893), Collis Potter Huntington (1821–1900), Mark Hopkins (1813–1878), and Charles Crocker (1822–1888).

Although it was criticized as a holding company to extract profits, the PIC had an important impact on the history of California.

The company was created for the "purpose of engaging and carrying on the construction, manufacturing, mining, mercantile banking and commercial business in all its branches."

[4] In January 1880, the branch line of the Southern Pacific Railroad between Castroville and Monterey, California was completed.

[5] The land included the site of the hotel in Monterey, two of the largest Spanish land grants, Rancho Punta de Pinos, and El Pascadero, which today includes the Del Monte Forest, Pebble Beach, and Pacific Grove.

[11] The Pacific Improvement Company built the Carmel River Dam in 1883, to deliver water to Monterey.

700 Chinese laborers built the dam by laying cast iron pipe to bring water out of Carmel Valley.

The Pacific Improvement Company hired William Hatton to manage a dairy and ranching operation in Los Laureles.

In 1917, the PIC decided to dismantle it and use the wood in the reconstruction of The Lodge at Pebble Beach that had burned down on December 17, 1917.