What nationality did the ancestors of the United States come from?

The ancestors of America were not entirely British.

Americans were immigrants from Europe during the colonial period. But the American continent was not only colonized by Britain. For example, Spain was one of the countries that colonized the American continent in the early days.

Only by various means did the United States annex the land originally occupied by other European countries. For example, due to the decline of Spain, the United States won the war with Spain at a small cost, and many Spanish colonies, including Guam, have since belonged to the United States.

About early English colonists;

1606 In fact, only 105 of the first batch of British colonists arrived in America (many people died on the road), of which a small proportion were free people, most of whom were indentured slaves, who exchanged their freedom for American ship tickets in recent years. All hail the king, the first British colony in America, was named Jamestown.

Even if those lucky colonists didn't die on the road, the death rate after landing on the American continent was still high. Ironically, some colonists accepted the help of native American tribes in order to survive.