Johnson ' s Island Johnson ' s Island is a island in Sandusky Bay , located on the coast of Lake Erie , 3 miles ( 5 km ) from the city of Sandusky , Ohio . It was the site of a prisoner - of - war camp for Confederate officers captured during the American Civil War . Johnson ' s Island was the only Union prison exclusively for Southern officers but it also held regular soldiers . During its three years of operation , more than 15 , 000 men were incarcerated there . Civil War years . In late 1861 , Federal officials selected Johnson ’ s Island as the site for a prisoner of war camp to hold up to 2 , 500 captured Confederate officers . The island offered easy access by ship for supplies to construct and maintain a prison and its population . Sandusky Bay offered more protection from the elements than on other nearby islands , which were also closer to Canada in the event of a prison break . Woods of hickory and oak trees could provide lumber and fuel . The U . S . government leased half the island from private owner Leonard B . Johnson for $ 500 a year , and for the duration of the war carefully controlled access to the island . The prison opened in April 1862 . A - high ( 5 m ) wooden stockade surrounded 12 two - story prisoner housing barracks , a hospital , latrines , sutler ’ s stand , three wells , a pest house , and two large mess halls ( added in August 1864 ) . More than 40 buildings stood outside the prison walls , including barns , stables , a limekiln , fort s , barracks for officers , and a powder magazine . They were used by the 128th Ohio Volunteer Infantry , which guarded the prison . Among the prominent Confederate generals imprisoned on Johnson ' s Island were Isaac R . Trimble and James J . Archer ( both captured at the Battle of Gettysburg ) , William Beall , Thomas Benton Smith , Edward " Allegheny " Johnson and Missouri cavalryman M . Jeff Thompson . Lieutenant Christopher Columbus Nash , later the sheriff of Grant Parish , Louisiana , who directed the Colfax Riot in 1873 , was also imprisoned at Johnson ' s Island . The prisoners had a lively community , with amateur theatrical performances , publishing , and crafts projects available . After the unraveling of a Confederate espionage ring which had been plotting the seizure of the Great Lakes warship USS " Michigan " and a mass breakout of prisoners , Forts Johnson and Hill were constructed over the winter of 1864 – 65 . They were not operational until March 1865 , in the war ' s final months , when the prisoner population peaked at 3 , 200 . More than 15 , 000 men passed through Johnson ’ s Island until it was closed in September 1865 . Wardens lost only about 200 prisoners as a result of the harsh Ohio winters , food and fuel shortages , and disease . Johnson ' s Island had one of the lowest mortality rates of any Civil War prison . Confederates made many escape attempts , including efforts by some to walk across the frozen Lake Erie to freedom in Canada . A handful of escapes were successful . Postbellum . After the war , the prison camp was abandoned and control reverted to the owner . Most of the buildings were auctioned off by the Army , and some were razed after falling into disrepair . Efforts in 1897 to turn the island into a resort ( as with nearby Cedar Point ) failed , and the land was used for farming and rock quarrying . Many lakeside homes have since been built , and the island is now quite developed with two subdivisions . Most of the Civil War - related sites , excepting the cemetery , have since been destroyed and built over . In 1990 Johnson ’ s Island was designated a National Historic Landmark . A causeway was built to connect it with the mainland . The Confederate cemetery , as well as Fort Hill in the interior of the island , are accessible to the public . Ground - penetrating radar studies have proved that several graves lie outside its fence . Heidelberg College conducts yearly archeology digs at the prison site . Friends and Descendants of Johnson ' s Island Civil War Prison The Friends and Descendants of Johnson ' s Island Civil War Prison was formed in 2001 to help in the preservation , interpretation , and education of the Johnson ' s Island Prison site . In conjunction with Heidelberg University , the Friends have sponsored educational and research programming at this National Historic Landmark . To search for ancestors that may have been incarcerated at Johnson ' s Island , contact the Friends internet site .