Corders in the McKay Family Genealogy Index

I spent an hour in the new (and greatly improved) Samuels Public Library in Front Royal today and started making my way through the shelves of their Local History Room. I'm looking for the Corders of old Frederick County, VA. Not a lot of luck so far, except for a couple of entries in the McKay Family Genealogy Index.

There was a reference to Edward Cordit (Corder) on page 680 of the index referring to Frederick County Order Book 1:316, an entry dated 2 April 1745 when he (among others) petitioned for a road from the Court House to Gregory's Ford. Not too sure where Gregory's Ford is. I've Googled it and I'm not getting any satisfactory results. I assume it's somewhere along the Shenandoah or the Opequon. Edward was later tasked with maintenance on the resulting road.

Another entry on page 826 concerns John Corder, believed to be the second son of Edward Corder Sr. of Greenway Court. John married into the Quaker Branson family (she was disowned for marrying out of unity) and he and his wife Elizabeth Branson Corder inherited land in Frederick County from her father, John Branson. On August 5, 1772 John and Elizabeth Branson Corder sold their parcel of land to Andrew McKay. (In 1762 John Branson sold acreage to Andrew McKay; in 1767 Thomas Branson sold land to Jacob McKay; in May 1768 John Branson sold another parcel to Andrew McKay. Looks like when the Bransons wanted to liquidate land, the McKays were the go-to guys.)

The third entry concerned a Mary Corder who had married a A. R. Y. Compton. After digging around a bit, I concluded that Mary was the daughter of Alexander Corder and Elizabeth Arnold of Culpeper County, VA. These Corders are descendants of the Fauquier County group as far as I can tell.