 Kaczynski was born on May 22 , 1942 , in Evergreen Park , Illinois , to second @-@ generation Polish Americans Wanda ( née Dombek ) and Theodore Richard Kaczynski . At six months of age , Kaczynski 's body developed a severe case of hives . He was placed in isolation in a hospital where visitors were not allowed , as physicians were unsure of the cause of the hives . He was treated several times at the hospital over an eight @-@ month period . His mother wrote in March 1943 , " Baby home from hospital and is healthy but quite unresponsive after his experience . " 
