You peaked my interest so I did a quick look on the internet for these forts. Two sources that might have the answers you need are The Tennessee Encyclopedia of History & Culture (under TN forts- Western TN) which is on-line and the book American Civil War Fortifications (3) by Osprey.

Ft Pillow, Chickasaw Bluff No.1, Conf. used 1861-1864

Ft. Wright at Randolph (also known as Ft. Randolph), Conf used 1861-June 1862 when abandoned just as the Yankees approached. It was a 6 gun earth redoubt just south of the Hatchie River on Chickasaw Bluff No. 2

Ft. Harris, Conf. used 1861-1862, was located near present day mouth of the Loosahatchie River and was abandoned before Memphis fell June 1862

Ft. Pickering (now downtown Memphis area) was built on 2 old Indian mounds as redoubts. Largest mound had 4 guns with interior magazine and the smaller had 3 guns. This fort captured by the Yankees in June 1862 and expanded.

The sources I cited have maps, renderings, etc. of the forts.

Of course, the Mississippi has changed its course since the 1860's to complicate matters.