Cavaliers were the aristocracy of England, the rich, the rulers. But there was a problem for their families. The first son was the heir to the estate. The second son was a reserve; there in the event of a death. Other sons could be put into the Church, Law, Army or even the Royal Navy. The rest had to make their own way in the world.
Adventurers, explorers seeking riches or even a decent living were the result. Daughters had to marry or stay at home. Similar situations in Europe meant there were plenty of fortune hunters, which may well explain why so many Portuguese became explorers.
Englishmen were prone to go to North America, which tended to mean Virginia, first settled in 1607, which is why the Southern States were so different in character to the North, to New England, where Puritans went. This fact ultimately led to the American Civil War from 1861 to 1865. The South was mainly agricultural, while the North went in for manufacturing as well. This gave them the firepower that caused the South to lose.