What exactly was the colonial period?

Question

and how important was tabacco in Britain and the USA's development in the colonial period?

Answer 1

The time period up to 1776. There were many British, French, Spanish and Dutch colonies in the New World. On July 4 1776 declared 13 British colonies independence following some quarrels with the British authorities in London. (Boston Tea Party, for instance). Tobacco  was not insignificant but it was not a major crop either - there were other commodities far more important.

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Answer 2

The colonial period was the time frame when the major European world powers set up colonies and outposts throughout the world including what is today known as the US, but also throughout North and South America, the Caribbean, Africa, and parts of Asia.  The colonial powers were England, Spain, France, Holland, and Portugal.  In the US this took place from about 1620-1776 but throughout the world the time period is much more broad.

Tobacco was important essentially because that was the main plantation crop that gave the southern American colonies an economic reason to exist.