A few summers ago I discovered an unpublished Master's Thesis by Stephen Charles Young titled Loyalism along the East Branch of the Upper Susquehanna River. Young describes in detail the settlement of the Susquehanna and the events leading up to the Battle of Wyoming in 1778. Young also provides brief biographies of the Loyalists including Joshua BEEBE and Mary SECORD's brothers. Here is the entry for Joshua BEEBE:
BEBEE (BEEBE), Joshua
A native of America, he had settled on the Susquehanna by 1775, owning 300 acres. He joined Butler's Rangers with a son on April 1, 1777, and served as a courier to New York. He died there of small pox, 28 Oct 1778 (Palmer, p. 56). A Joseph BEBEE (possibly Joshua) was a Private in Butler's Rangers (Fryer & Smy, p. 60). Also identified in the "Up the River" tax list of August 1776 (WHGS V:217).
Young's sources for the BEEBE entry are Palmer's Loyalists of the American Revolution, Fryer and Smy's Rolls of the Provincial (Loyalist) Corps and the tax list transcribed by the Wyoming Historical and Genealogical Society and reprinted online at:
http://www.teachout.org/du/nan/uptheriver.htmlSince Joshua BEEBE appears on the "Up the River" tax list of August 1776 we can conclude that he was definitely on the Susquehanna at that time. According to Young many of those who settled "Up the River" were never granted title to their land by the Susquehanna Company and were essentially squatters. There were also settlers in the on the Susquehanna whose title had been granted by Pennsylvania since both Connecticut and Pennsylvania claimed ownership of the area.
The dispute over ownership between Connecticut and Pennsylvania led to had armed confrontation during what is known at the Pennamite Wars. I think that it is quite unlikely that Joshua BEEBE settled on the Susquehanna before the end of the wars in 1771.
Young states that the SECORDs settled on the Susquehanna at Mehoopany or Tunkhannock in about 1773/74. His source is Oscar Harvey's A History of Wilkes-Barre. My theory is that Joshua BEEBE settled at the same time as his brothers-in-law and were neighbours.
The evidence therefore suggests that of Joshua BEEBE and Mary SECORD's seven children only one, Sarah, was born on the Susquehanna.
John Secord BEEBE's letter states that his father, Joshua, was born at Tioga Point. I would say that this claim is fairly solid since Tioga Point was a loyalist settlement used as an advance base by Butler's Rangers.
According to the Barbour Collection of Connecticut Vital Records Adin BEEBE and Secord BEEBE were born in Ashford, Wyndham, Connecticut.
As to where Charlotte, Asa and Amasa were born, I have not seen any evidence to support a place of birth.
I think the question that really needs to be answered is where was a Connecticut Yankee (Joshua BEEBE) living when he met the daughter of a French Huguenot family (Mary SECORD).