Conroy has earned praise for his meticulous research and the historical accuracy he brings to his work. While many of the characters in his novels are historical figures, the character development for these as well as the fictional characters advances through the novels.

His first novel, 1901, deals with a German invasion of Long Island. His second novel, 1862, is based on what might have happened had The United Kingdom entered into the American Civil War on the side of the Confederacy. 1945, deals with what might have occurred if the Japanese had not surrendered at the end of World War II and a land invasion of the Japanese home islands was required. His fourth novel, 1942, which won the Sidewise Award for Alternate History, tells of the Japanese conquest of Hawaii after the attack on Pearl Harbor is far more successful than actually happened. His fifth novel, Red Inferno: 1945, deals with a war between the Allies and the Soviet Union following the controversial move by the Allies towards Berlin. The move is tragically misunderstood by Stalin.

Works

• 1901 (1995)
• 1862 (2006)
• 1945 (2007)
• 1942 (2009)
• 1945 (2010)