[3] By the mid-1780s, he owned land along the Potomac River and in much of the area of what is now known as Glover Park and Wesley Heights, which was used for pastures and orchards.

"[6] Threlkeld raised Merino sheep and English cattle on the land and grew apples, mulberry, and peach apricots.

[4] Threlkeld used slave labor and owned at least fifty enslaved persons during his adult life, the vast majority of whom had been inherited from his grandfather.

[23] Threlkeld, along with John Tayloe III, John Peter Van Ness, Charles Carnan Ridgely, Dr. William Thornton, G. W. P. Custis, and George Calvert of Riversdale, initiated moving the contests to Meridian Hill, south of Columbia Road between Fourteenth and Sixteenth Streets, and conducted the races at the Holmstead Farm's one-mile oval track.

[4] The 1826 closure of the bank led to a "calamitous" period of severe financial and personal hardship for Threlkeld and his family.

After the closure of the bank, Threlkeld was forced to auction hundreds of acres of property and land holdings to satisfy his debts.

[5] His grandson was Major Richard Smith Cox, a Confederate paymaster on the staff of General George Washington Custis Lee.

[29] The property owned and developed by Threlkeld encompassed what now includes Georgetown University, Washington International School, Foxhall Village, and Burleith.