Native Americans were the first to do so. Then the first Europeans came, the Spanish. After that the Americans started exploring farther west before attaining this part of the modern day US. The French also had a short lived settlement in Texas.
It may be a reference to Garcia Lopez de Cardenas or to John Weley Powell.
Fransisco Vasquez De Coronado
Francisco Vásquez de Coronado was the Spanish conquistador who visited the southwestern part of the United States between 1540 and 1542. He did this in the hopes of conquering the mythical Seven Cities of Gold.
In the 1500s, the Spanish explored Florida. Around then Ponce de Leon was searching for the fountain of youth with his crew.
Canada
Yes, Francisco Vázquez de Coronado led an expedition into the southwestern United States in the 1540s. He explored areas that are now part of Arizona, New Mexico, Texas, Oklahoma, and Kansas in search of the fabled Seven Cities of Gold. His journey contributed significantly to European knowledge of the region, although he ultimately found no riches.
Lewis and Clark explored the Louisiana Territory.
Spanish Conquistadors embarked on exploration of the southwestern US
Coronado explored the southwestern US, while de Soto explored the southeastern US.
Juan Ponce de Leon
Juan Ponce de Leon
Hernando de Soto explored much of Colorado, New Mexico, Arizona, and southern California.
Francisco Coronado
Coronado
Francisco Vásquez de Coronado was the Spanish conquistador who visited the southwestern part of the United States between 1540 and 1542. He did this in the hopes of conquering the mythical Seven Cities of Gold.
El Dorado or the Cities of Gold was a location hunted by many who explored the southwestern part of the United States. It was never found.
Spain and then Mexico
In the 1500s, the Spanish explored Florida. Around then Ponce de Leon was searching for the fountain of youth with his crew.
Francisco Vazquez de Coronado y Lujan, or Francisco de Coronado, was a conquistador in the 1500s. In particular, he explored and claimed the Southwestern United States for Spain.