Around 1864-65, city defenses (see this Wikipedia article), including eleven forts ordered by Union General Stephen G. Burbridge, formed a ring about ten miles (16 km) long from Beargrass Creek to Paddy’s Run. Nothing remains of these constructions.
These forts were: (data extracted from Wikipedia 9/27/16)
- Fort Clark: Located on the corner of 36th and Magnolia Streets. It was named for Lt. Col. Merwin Clark of the 183rd Ohio Infantry who died at the Battle of Franklin in November 1864.
- Fort Elster: Near Bellaire, Emerald, and Vernon Avenues, between Brownsboro Road and Frankfort Avenue, where Beargrass Creek empties into the Ohio River. It was named for George R. Elstner, a Lieutenant Colonel of the 50th Ohio Infantry who died in Georgia in August 1864.
- Fort Engle: Corner of Arlington Ave. and Spring Street. It was named for Captain Archibald H. Engle of the 13th U.S. Infantry, who died in Georgia in May 1864.
- Fort Hill: On the hill between St. Louis Cemetery and Goddard Avenue, on what is now Castlewood Avenue. It was named for George W. Hill, a captain in the 12th Kentucky Infantry who died in Atlanta, Georgia in August 1864.
- Fort Horton: Where Merriwether and Shelby Streets meet. It was named for M.C. Horton, a captain of the 104th Ohio Infantry who died in Georgia in May 1864.
- Fort Karnash: Between 26th and 28th Sts. on Wilson Avenue. It was named for Julius E. Karnash, a Second Lieutenant of the 35th Missouri Infantry who died in Atlanta, Georgia in August 1864.
- Fort McPherson: in the area of Preston Street, by the old Shepherdsville Turnpike and Louisville and Nashville Railroad, south of the old city limits. It was named for the Major General, James B. McPherson, who died in Atlanta, Georgia in July 1864. It was the largest of fortifications for Louisville. It was also the first to be built. It typically held 100 artillerists and 500 infantry, but could hold upwards to a thousand soldiers. Its Parrott rifle, actually an artillery cannon, could shoot a 100-pounder shell five miles (8 km) away. It was complemented with ten additional artillery pieces. It also featured a caponier battery, built in the October 1864.
- Fort Philpot: located by Algonquin Parkway and present-day Seventh Street Road (then the Louisville and Nashville Turnpike Road). It was named for J. D. Philpot, a captain for the 103rd Ohio Infantry who died in the Battle of Resaca in May 1864.
- Fort Saint Clair Morton: on a small hill at corner of where 16th and Hill Streets would be if they intersected, it guarded what is now Dixie Highway (then Salt River Turnpike Road). Named for Major James St. Clair Morton of the Corps of Engineers, who died in the Battle of Petersburg in June 1864.
- Fort Saunders: within Cave Hill Cemetery, named after E.D. Saunders of the A.A.G. Volunteers, who died in Georgia in June 1864.
- Fort Southworth: On Paddy’s Run, by the north side of a bend 1/4 mile from the Ohio River. It was named for A. J. Southworth, who died in Atlanta, Georgia, in August 1864. It was the westernmost of the fortifications and covered 19,000 square feet (1,800 m2) in total. Its construction began on August 1, 1864 and was paid for both by Louisville and by the federal government.