"The Big Four" was the name popularly given to the famous and influential businessmen, philanthropists and railroad tycoons who built the Central Pacific Railroad, (C.P.R.R.), which formed the western portion through the Sierra Nevada and the Rocky Mountains of the First Transcontinental Railroad in the United States, built from the mid-continent at the Mississippi River to the Pacific Ocean during the middle and late 1860s. Composed of Leland Stanford, (1824–1893), Collis Potter Huntington, (1821–1900), Mark Hopkins (1813–1878), and Charles Crocker, (1822–1888), the four themselves, however, personally preferred to be known as "The Associates."
Collectively, the four philanthropically also established the Sacramento Library Association for the state capital in Sacramento, California in 1857, which later established the present Sacramento Public Library.
David Hewes, an enterprising businessman, was called the "maker of San Francisco" for his work in clearing land for development. He was invited to be a part of the "Big Four" but declined due to the financial risks. Over his lifetime he gained and lost several fortunes.
In their time, the four men were sometimes referred to as nabobs or "nobs," a reference to their wealth and influence. When the four built mansions in the same neighborhood of San Francisco, the area quickly became known as Nob Hill, a name it carries today.
Ambrose Bierce lampooned the "Big Four" in his work "Black Beetles in Amber", a collection of satirical verses attacking various prominent Californians. In "The Birth of the Rail", "road agents" (bandits) Happy Hunty (Huntington), Cowboy Charley (Crocker), and Leland The Kid (Stanford), joined by minor devil Sootymug (Hopkins), give up robbing stage coaches for the much greater loot of railroad operation.