There were twenty English colonies in North America by 1775, thirteen among them later rebelled against the British rule and formed the First Union of the United States of America. Those colonies were Delaware, Pennsylvania, New Jersey, Georgia, Connecticut, Massachusetts Bay, Maryland, South Carolina, New Hampshire, Virginia, New York, North Carolina, and Rhode Island and Providence Plantations. By the 18th century, the American colonies were growing very rapidly because of the abundant supplies of food and low death rates which attracted a steady flow of immigrants.