In 1830 Mexican trader Antonio Armijo completed the journey from Santa Fe to Los Angeles through a corner of the Las Vegas Valley. After that, Las Vegas, which means "The Meadows" in Spanish, was an important stop on the Old Spanish Trail in the 1830s and 1840s and later on the California trail during the Gold Rush.

Lt. John C. Fremont was the first to put Las Vegas on the map during his famous Army expedition in 1844. His widely disseminated report brught thousands of emigrants through the area. Today, his name is associated with Fremont Street and the Fremont Hotel in downtown Las Vegas. 

In 1855 Mormon settlers from Salt Lake City traveled to Las Vegas to protect the Los Angeles-Salt Lake City mail route.   They built a small adobe fort, planted trees, cultivated vegetables, and mined lead for bullets.   The Mormons later abandoned the settlement, partly because of Indian raids.   The fort still stands and is located at the intersection of Las Vegas Boulevard North and Washington Avenue.

In 1864, during the Civil War, Nevada was admitted to the Union.   It was called the Battle Born State.

In 1902, Montana Senator William Clark for whom Clark County is named bought the 2,000-acre Stewart Ranch and its water rights in what is now downtown Las Vegas. Clark then negotiated a compromise in which he won the right to construct the railroad that would connect the Union Pacific mainline in Utah with Southern California. The Las Vegas Valley, because of its water supply and its location halfway between Los Angeles and Salt Lake City, was a natural stopping off point for railways traveling between the two destinations.

The railroad began near dusty Fremont Street in January 1905. On May 15 of that year, Las Vegas was founded when Clark auctioned off lots at "Clark's Las Vegas Townsite" in present-day downtown.

In 1909, growth in the area created the need to divide Lincoln County into two counties.   The new county was called Clark and Las Vegas became its county seat.

In 1911, the state of Nevada enacted a strict anti-gambling law. However, public outcry resulted in an amended version in 1915 allowing card games without a percentage for "the house" and slot machines with non-monetary prizes. Underground games flourished until 1931, when table games were again legalized through a bill sponsored by Northern Nevada rancher Phil Tobin. 

Today, gambling revenues account for over 43% of the states general fund.

In conjunction with legalized gambling, the building of the Hoover Dam created a rare economic boon in Las Vegas during the Great Depression.   The Hoover Dam project alone employed 5,128 at its peak.

During World War II Nellis Air Force Base became a key military installation where B-29 gunners and top fighter pilots were trained.

In the late 40s and 1950s Las Vegas began to grow into a resort destination.   Entertainment, along with gambling, liberal marriage and divorce laws, and convention facilities brought thousands of visitors each year leading to the advent of the megaresort atmosphere of modern day Las Vegas.