Prior to the Revolutionary War, the US experienced a colonial form of government, which differs from a Republic in several significant ways:
A colony is ruled by a foreign power. In the case of the US, this power was England. A republic, on the other hand, is autonomous, and it forms its own government.
A colony is usually ruled by a monarch (it is not a necessary requirement, but it has been so in practice), while republics elect their leader through voting.
Republics tend to be democratic and participatory, with no inherited power positions.
A republic has the power to make its own laws in terms of taxation, rights and duties, education, healthcare, etc. while the colony has to follow those of the mother country.
