Thomas Paine was a very influential writer of the mid 1700's. He wrote in a manner that was easy to read. Many writers of the time wrote in a way that only the very well educated could read. Because of this, many people read this pamphlet and it had a huge impact.
Thomas Paine villified the British crown. The trouble of the early 1750's, according to Paine, were the fault of the British government. He went on to write, that the colonies should be free of the British. The population in the colonies were split on the idea of independence. The pamphlet "Common Sense" helped to sway the leaders and the people that the time had come to declare independence.
Thomas Paine wrote the pamphlet "Common Sense" in 1775 and it was published in January of 1776. The main impact of this pamphlet was to help cause the American colonists to decide to fight for independence.
The first battles of the Revolution took place in 1775, but the colonists had not yet decided to actually try to become independent. Many of them still wanted to try to reconcile with England and there was not a huge amount of hatred for the idea of monarchy.
The publication of Common Sense changed that. In the pamphlet, Paine argued that monarchy was a bad system of government and that the American colonies must become free. After that, sentiment grew for this position, leading to the Declaration of Independence in July of 1776.
The most significant of the pamphlet "Common sense" written by Thomas Paine is that it was a strongly worded call for independence from Great Britain.