Zachary Taylor Kemplin was a brother to my g-g-grandfather, Abraham Lincoln Kemplin. Various members of this family moved to Cooke county, Texas, at the beginning of the 1900s. Some returned to Kentucky and Tennessee. I have not searched for him very diligently, but I would try Texas.
Zachary's parents were William Kemplin (abt. 1820-abt. 1890, Tennessee) and Susannah Baxley (May 1831? TN - after 1910 Cooke co., TX?). Their children were: Elizabeth b. 1848 William b. 1849 Martha Ann b. 1852 George Washington b. 1854 (married Mirah Kidd who died Mar 9, 1929 Clinton co., KY) Nancy E. Zachariah Taylor b. Nov 19, 1858 in Wayne co., KY James Buchanan b. 1861, m. Rebecca Crabtree Abraham Lincoln (b. Sept 25, 1864, d. Apr 26, 1927 Cooke co.,TX, m. Cordelia Looper) Andrew Johnson (b. Nov 1865, d. Oct 6, 1942 Clinton co., KY, m. Elizabeth Pruitt) Jonathon b. 1867 John Adams b. 1871
I got Zachary's birthdate from "Wayne County, Kentucky, Marriage and Vital Records 1801-1860," compiled by June Baldwin Bork. He was born on Beaver Creek.
The family tree that Phillip Kemplin maintains on his website links up the ancestors of this family.Hope this helps!