Cornelius was the son of Abraham Peterson (b. 1769) and Susannah (last name unknown). He was the brother of the Rev. Abraham Peterson, Jr. and Samuel Peterson.

Cornelius first married Cilinda LANE; he secondly married Mary RODERICK. Ten children were born to his first marriage and one to his second marriage.

According to the paper trail, Cornelius had two lines back to Mayflower passenger Richard Warren. One was as follows, beginning with Cornelius' father:

Abraham Peterson (b. 1769, Kennebec Co. Maine) Abraham Peterson (b. 1745) Joseph Peterson, Jr. (b. abt 1705) Joseph Peterson and Sarah Jones (1671-1752) Joseph Jones and Patience Little (b. 1639) Thomas Little and Anna Warren (abt 1612) Richard Warren (d. 1628 Plymouth, Massachusetts).

Cornelius' other line back to Richard Warren was the following:
Abraham Peterson (b. 1769, Kennebec Co. Maine) Abraham Peterson (b. 1745) and Patience Baker (b. 1749, Plymouth Co., Massachusetts) John Baker (b. 1719) Kenelm Baker and Patience Doty (b. 1897, Plymouth Co., Massachusetts) John Doty and Sarah Jones (b. 1671, Plymouth Co., Massachusetts) Joseph Jones and Patience Little (b. 1639) Thomas Little and Anna Warren (abt 1612) Richard Warren (d. 1628 Plymouth, Massachusetts).

Additionally, both the paper trail of genealogy documents and DNA-match confirmation say that Cornelius' father Abraham was descended from Mayflower passengers William Bradford, Edward Doty, and George Soule:

William Bradford:
Abraham Peterson b. 1769 Patience Baker b. 1749 John Baker b. 1719 Kenelm Baker b. 1695 Sarah Bradford b. 1671 William Bradford b. 1624 William Bradford b. 1590, d. 1657.

Edward Doty:
Abraham Peterson b. 1769 Patience Baker b. 1749 John Baker 1719 Patience Doty b. 1697 John Doty Sr. d. 1701 Edward Doty d. 1655.

George Soule:
Abraham Peterson b. 1769 Abraham Peterson b. 1745 Joseph Peterson b. 1705 Joseph Peterson b. 1668 Mary Soule b. 1644 George Soule b. 1595, d. 1679.

MAYFLOWER NOTE:
The Mayflower Society considers as proven the line from Abraham Peterson (b. 1745) m. Patience Baker, back this route:
Abraham PETERSON (b. 1745),
son of Joseph PETERSON (b. abt 1705),
son of Joseph PETERSON (b. abt 1668),
son of Mary SOULE (1644-1720),
daughter of George SOULE (1595-1679).