Francis and Andrew Intersect
It is not known whether the immigrant ancestors Francis Newcomb and Capt. Andrew Newcomb were related.
We do know that the two lines have come together more than once, when descendants of Francis have married descendants of Andrew.
For example, Benjamin Loring Newcomb (Benjamin, Jonathan, Samuel, John, John, John, Francis) (b. 14 Jan 1834) married Abigail Wilson Colbath (Eliza, Silas, Silas, Silas, Thomas, Thomas, Andrew, Andrew) (b. 10 Jan 1843). They had at least one child, Arthur Winthrop Newcomb b. 20 Apr 1864.