Since the spring of 1989, Dr. David Bush has directed investigations at Johnson's Island.
As a result of both historical documentation and field research, the prison stockade, Fort Johnson, the remains of Fort Hill, and the dock have been located. Archaeological excavations have been carried out in several sinks (latrines) dating from 1862 to 1865, a prison well, the powder magazine from Fort Hill, and portions of two prison blocks Archaeological remains from these features have provided much information on the human condition within the prison yard as well as the personal possessions of the inmates. The 2004 summer field school in archaeology focused on excavations of the 1862 latrine from Block 4, a regular prisoner housing block. We also discovered one of the 1865 latrines.
The initial goals of the study of the Johnson's Island Civil War Military Prison site were to determine the boundaries of the site and what types of archaeological remains exist.
This was necessary due to proposed development of the island. Through an effort to understand the historical importance of the site, an effort was made to locate some of the writings from both the Union and the Confederate Officers imprisoned on the island as well as reviewing all that had been written about this prison site. In 1990, it was determined that there was both a wealth of historical documentation about Johnson's Island prison, and that there was also an archaeological resource that remains unparalleled for any other American Civil War Prison site. For these reasons, the Johnson's Island Civil War Military Prison site was selected as a National Historic Landmark property.
In 1864, the Union expanded the prison compound from 14.5 acres to 16.5 acres, moving the western fence approximately 100 feet further to the west. At the same time, the Union excavated a ditch to bedrock around the three inland stockade walls of the prison to prevent prisoners from attempting escape through tunneling. This ditch served as the most definitive archaeological feature for defining the boundaries of the prison compound. Our initial investigations in 1989 and 1990 were to locate this ditch on all sides, allowing a precise determination of the prison compound.
When the ditch was finally located, the next phase of research involved locating some of the sinks (latrines) associated with several of the prisoner Blocks (housing units). Each Block had a latrine located behind it, and these latrines were used for short periods of time, filled in, and new ones dug. Eventually, each Block had five or more latrines to their rear. It was important that we document the condition of these latrines, as well as ground truthing some of the historical mapping that existed allowing us to have a full understanding of the prison compound layout. Our investigations in 1990 through 1996 were aimed at locating and testing latrines associated with Blocks 1, 6 (the prison hospital), and 8. In all, ten latrines were located, with five being completely excavated and three others being sampled.
These studies of the latrines have given us a partial view of the changing treatment of POWs throughout the Civil War. We have a better understanding of the medical treatment of the POWs, and we also have documented prisoners attempts to escape through tunneling. Several publications have been produced through these studies and more are certainly on the way.
These studies have also enabled researchers to see what types of materials were available to the prisoners. This is not something that has been well understood historically, and now for the first time can be clearly documented from the Civil War. The materials recovered from the study of the latrines, as well as our study of the prison Blocks themselves, have shown that the prisoners had at times access to a variety as well as vast quantities of materials.
Since 1997, our focus has been on the investigation of the locations where the prison Blocks were located. The past two summers have been spent investigating Block 2, a general housing block. We have recovered a wealth of information about the day to day existence of the prisoners based on the small pieces of material that fell through the cracks of the floor of that block. For the most part, these materials are located in the plow zone. After the prison was abandoned and the buildings removed, Mr. Johnson continued to use the prison compound for agricultural purposes. Aerial photographs from 1939 through the 1950s show the prison compound being plowed. The plow zone is excavated, screened, and all historic materials recovered. The subsoil underneath the plow zone has provided evidence of the posts used to support the structure, as well as drainage ditches and possible pits used to hide contraband materials.
The archaeological resources of Johnson's Island are certainly unique. Nowhere else does there exist time capsules (in the form of latrines) from the American Civil War, giving us a few months at a time of how prisoners were treated. Nowhere else does there exist such a wealth of primary documents, giving us a day to day account of how these prisoners saw their predicament. Combined, this provides the best field laboratory for demonstrating not only the science of archaeology, but also a chapter of American history as seen through prisoners of war.