The correct answer to this open question is the following.
The Declaration of Independence states that people have a right to abolish their government. A revolution is necessary when the government has committed a series of atrocities, corruption acts, immoral acts, which consequences are the impoverishment and starvation of the citizens.
Are a "long Train of Abuses and Usurpations" required for a revolution to be legitimate? Yes, but it is not the only condition, as I stated above.
In the case of the United States, American colonists were angry and desperate for the series of injustices and heavy taxation imposed by the English government. Taxation such as the Navigation Acts, the Stamp Act, or the Tea Act, infuriated the colonists and were big reasons for the beginning of the American Revolutionary War of Independence. To make things worse, colonists had to pay taxes but had no voice or representation in the British Parliament.