Between Spain and England, England seems to have figured out the better way to establish settlements in the New World. Although the Spaniards had explored and claimed most of the United States' southern border (from Florida to southwest California), they had not actually settled in all of the land that they explored and claimed. In addition, the Spaniards never sent word to anyone to inform them that they had claimed the land that they explored. By failing to create settlements or communicate about the land they explored, the English were able to discover and make their claims for that land. Unlike the Spanish, the English established settlements (which developed into colonies) in the land they then claimed.
If the English hadn't established the settlements at the time they discovered the land, there would not have been any challenge to Spain's claims to the land. They most likely would have developed settlements in those regions and could have resulted in those lands being separated and not part of what is now known as the United States. It is likely those settlements would have been devoted to the King and Queen of Spain and therefore, would not become part of a new country. The make-up of our country would have been vastly different if the Spanish would have been able to maintain their claims.