Dear Mary, I had Arthur O'Neal being married to Mary Matson, dau of Peter, one of whose brothers was Morris, my 5th ggrandfather. Thus, we are related. However, I and I doubt you have no relationship to the Peter Dalbo Mattson that married Catherine Rambo. I got most of the information on those lines from Ella Matson's five volumes on Matson genealogy which I have. They are available through any of the Family History Centers on film. Her sisters say that prior to her death she began to doubt the Swedish origins of the Mattson/Matson line. My wife, Ginnie and I believe the probable origin of our Mattson/Matson line is Welsh. The oldest Matson we have is John Mattson, b. about 1686, father of Peter Mattson, b. abt.1710 who married Ann Ely.
I have copies of letters from Peter Craig who does not think our Matson line is related to any of his Swedish Mattsons.He points out a tax roll from 1734 for Upper and Lower Merion reproduced in the Genealogical Society of Pennsylvania, 1:174-175 does not show any Mattson in either township. The same tax list does show, however, as the second entry for Lower Merion township, the name of 'John Roberts, Mats son.' This was an area settled by Welsh Quakers. There were about three John Roberts in the area at that time and as the Welsh, like the Swedes, had a history of using patronymics, it is very possible that this John became John Mattson to differentiate himself from the others. Roberts was a common Welsh family name.
Back to the Swedes. As I said, I got most of that information from Ella Matson, other than the dates of birth of Peter and Catherine's kids which came from Philadelphia County, PA Births, 1644-1765, John T. Humphrey, page 323, Allen Co., IN library. Peter Mattsson, b. 27 May 1687 in Mantua Creek, Gloucester, West New Jersey, d. 28 Mar 1722, m. Catharina, b. abt. 1687 in Gloucester, New Jersey, m. abt 1707 in NJ.
His brother, John Mattsson, b: 14 Jun 1694 in Mantua Creek, Gloucester, West NM, m. Annica Cock b: abt 1696 in Swedesboro, Gloucester, NJ, m: 01 May 1717 in Chester, PA>
We are in process of writing a Matson book on our line and are mostly down to adding in pictures and some stories. I'd be happy to share any information that might be of use to you. Just email me direct at email@example.com.