Arizona was the last contiguous state to join the Union: Arizona became the 48th state in the US on February 14, 1912. It was the last of the contiguous states to be admitted to the Union.
Greenlee County is located in the southeastern part of Arizona. It was named after Mason Greenlee, an early settler of the region. The area that is now Greenlee County was originally inhabited by Native American tribes such as the Apache and Hohokam. European exploration and settlement began in the late 1800s, with the discovery of gold and silver in the region.

In the late 1800s, mining became a major industry in Greenlee County. Towns like Clifton and Morenci were established to support the mining operations. These towns experienced rapid growth and attracted a diverse population of miners and settlers. During this time, the development of railroad lines contributed to the growth and prosperity of the region.

Greenlee County faced several challenges in its early history. It battled with neighboring Graham County over the county seat, which was eventually settled in favor of Greenlee County in the early 1900s. The region also experienced several devastating floods in the early 20th century, which caused significant damage to towns and infrastructure.

In the 20th century, the mining industry continued to be the main economic driver in Greenlee County. The Morenci Mine, one of the largest copper mines in the world, became a major employer in the region. Today, Greenlee County remains a center for mining operations and serves as an important part of Arizona's economy.

This timeline provides a concise overview of the key events in the history of Greenlee County, Arizona.

  • 1872 - Greenlee County is established and named after Mason Greenlee, an early settler in the area.
  • 1873 - The Clifton townsite is laid out and the town becomes the county seat.
  • 1873 - The Longfellow Mine, a copper mine, begins operations, leading to an increase in population and economic growth.
  • 1880 - The first school in Greenlee County opens in Clifton.
  • 1909 - Morenci, a mining town, is founded as copper mining operations expand in the area.
  • 1913 - The Morenci Southern Railway is completed, connecting Morenci to Clifton.
  • 1942-1946 - Greenlee County plays a significant role in copper production during World War II.
  • 1970s - The mining industry experiences a decline, leading to a decrease in population and economic challenges.
  • 1988 - The Freeport-McMoRan Copper & Gold company acquires Phelps Dodge Corporation's mining assets in the county.
  • 1992 - Construction of the Arizona State Route 75, connecting Clifton to Morenci, is completed.
  • 2011 - The San Francisco River Heritage and Visitors Center is opened in Clifton to promote tourism and preserve the area's history.