Initial results showed them as being Haplogroup R1b-P312 and as having Y-DNA STR matches close enough to have a common ancestor in genealogical time.  R1b is the most common haplogroup in western Europe (see maps), and the two great subdivisions of R1b are U106 and P312.  Because of their common haplogroup, coupled with a common surname — BROWN is the 4th most common surname in the United States — deeper testing was needed to confirm their match, so all four have upgraded to 111 markers.  In addition, two have taken the BigY, the results of which initially indicated our BROWNs belong to a rare R1b-P312 subclade, namely, R1b-FGC16982, an immediate subclade of R1b-DF99 — see R-DF99 and Subclades project at FTDNA. 

An examination of their variant SNPs, ones unique to them, shows a shared variant that has now been named as a new SNP:  Y44983.  One or more of their currently unshared variants may prove a match with one or both of our other two BROWNs, so it would be very helpful for the other two to also take the BigY.  Knowing exactly how these four connect, in detail, could help us with their paper genealogy.

Below is a simplified Haplogroup R1b haplotree showing the position of DF99, parallel to the largest subdivision of P312, namely L21 — the largest subclade for western European males — along with two less common parallel subclades (DF27 and U152) and five other rare ones.

The fact that the DF99 is parallel to L21 and the others indicates this is a very old branch in the tree, one that either never was very common or has dwindled down from once having been common in a process known as genetic drift.  In other words, the small clade size does not indicate a lack of "fitness" (i.e., we are not being weeded out by natural selection!), it's just a  chance reduction of lines "daughtering out." 

The bottom line for us BROWNs is that our rare STR haplotype is in accord with our rare SNP haplogroup subclade, which means we should have no problem separating ourselves from other BROWNs.  It likely also means we may have a long wait before we get enough near, non-BROWN, SNP-tested relatives to reveal our geographic origin beyond what we already know:  that we're almost certainly English.

Update (5 Oct 2018):  Alex Williamson has analyzed our two Big-Y tested BROWNs with the result that he found they shared twenty-five SNPs downstream of FGC16982, twenty-three of them already named.  This means, so far at least, that we are only very distantly related to any other known family, BROWN or otherwise.

So far, the paper pedigrees of our BROWN males have not intersected, though all four trace back to New England.  We have solid paper trails leading us to:  1) New Hampshire in 1807; 2) Massachusetts ca. 1732; 3) Connecticut ca. 1710; and 4) Rowley, MA, in 1646.  The other question now raised is whether this American BROWN family is the result of only one immigration or as many as four distinct immigrations.