It would seem that at least one blockhopuse was built at Columbia. As follows:

"By mid-March (1864) Yate's battalion was scattered in detachments along the railroad from Franklin to Decatur. Between these points there were at least thirty blockhouses to be built, with the greatest concentration in the ten mile section between Columbia, Carter's Creek and Rutherford Creek. As the companies finished their work, they were moved further south on the Decatur line."

Page 201 (see also Footnote 8, Page 399) - "My Brave Mechanics: The First Michigan Engineers and Their Civil War" by Mark Hoffman (Wayne State University Press, Detroit, 2007)

Greg Biggs