N which period were MOST of the original British North American colonies founded?

The 13 colonies were founded from 1607-1732, bot including Plymouth which was founded in 1620 and later de-established in 1691.

I believe a valid answer would be beginning of 17th century to early 18th century.

Answer: Contemporary Age (1789 - Current Period)

Explanation: Most of the British American colonies were founded in the Contemporary Age, which is the period between the founding of the 13 British American colonies (as well as the Independence of the United States) and our actuality, that is, the period in which we live.