These were taken some time ago at the Arlington County Library Virginia Room. I have later records from this source if this is helpful.
1720 Reconstructed none
1740 Reconstructed none
1760 Thomas Linthecum/Thomas Linthicum listed in Cumberland County Order Book, 1758-1762. This available on LVA Reel 23, presumably Library of Virginia, Cumberland 18:282 and 18:140 respectively.
1790 (dates indicate when data collected) White/black 1783 George Lin_ Shenandoah Co1/0 1782 Thomas Linthecum Fluvanna Co.4/6 1782 Thomas Linthicum Fluvanna Co.6/1 1784 Thomas Linthicum Pittsylvania Co. 4/0 1785 Thomas Linthicum Jr Pittsylvania Co 7/0
1800—Data not available, British burn Washington in 1814