The original ramparts at Fort Pickens near Pensacola Beach, Florida were constructed of brick masonry. This was fine for a few decades following construction in 1830 when smooth bore guns and spherical cannonballs were the norm but, with the invention of rifled artillery shells in the 1860s, it became obsolete. It does, however, make for far more appealing pictures than the later, concrete portions of the fort.
For the technically inclined...