it sounds ugly but to penologist it was beautiful and escape proof. the military thinking prior to the civil warsaw the island as a strategic way to controlling the water. alcatraz was part prison from the beginning. when the first boats arrived, inmates were among them. during the civil war the army transformed the rock into the most heavily armed fortress west of the mississippi. but the giant cannons never fired or shot in anger. the anticipated attack by the south never happened and by war's end alcatraz was obsolete as a force. but as a prison it was still ideal for all but the prisoners. >> well, after the years of civil war this room was converted from a gun room into jail cells for military prisoners. 14 long wooden cells were in this space. back in here, this room which was an access into some slots was converted into a solitary confinement section. there were nine solitary confinement cells in this little space. vertical. the men would have to stand up inside these cells. it was just enough room for their knees to hit the door. >> reporter: