There is an interesting notion that a significant portion of the colonies' population were from jails and prisons in England. A penal colony is defined as a place far removed from the general population that contains exiles from a country. Penal colonies are places where the exiles have little or no freedom, are forced to work, and have no alternatives outside of being imprisoned.
In that respect, historians debate how much of the British colonies in the Americas fit the description of a penal colony. A significant number of the early colonists were indentured servants released from debtor prisons to pay debts they incurred in Great Britain. When they were unable to pay their debts, they were sentenced to lengthy jail sentences in Great Britain until someone either paid the debt or they were released. Rather than spend time in a debtor prison in Britain, many were offered the opportunity to come to the colonies and work to repay the debts they owed. For most, this was a much better option than debtor prison and it offered the prospect of once the debt was satisfied, freedom in a new country where the person could restart their life.
Some historians estimate that as many as fifty thousand prisoners were shipped from Great Britain to America. This is an astounding number given that it represents nearly a fourth of the total of early British colonists in the 1800's relocated to America!
The answer to your question is the British used debtor prisons and indentured servants as a source for labor in colonizing America. In this respect, you can accurately say America was colonized and the home for British penal colonies. It is inaccurate to characterize all of the early settlements and America as a penal colony.
Also, you have to separate the forced labor of slavery as a different issue and much more pernicious form of servitude than indentured servants. Indentured servants did not experience the same level of hostility and animosity as slaves. Some conflate the institution of indentured servant with slavery. They are totally different elements in the colonization history of America.