In a general sense, it was because of the oppression that Britain had put over the colonies that led to the Declaration of Independence. Some of the many factors included tax impositions, the Boston Massacre, Coercive Acts, and Common Sense by Thomas Paine.
Moreover, the declaration was written by a committee of five including Thomas Jefferson (primary author), John Adams, Benjamin Franklin, Roger Sherman, and Robert Livingston and ratified on July 4, 1776 in Philadelphia.
New forms of transportation such as the steamboat and the railroad helped the nation expand trade. Meanwhile, innovations such as the modern assembly line and electric light bulb revolutionized both business and personal life
