- Obregon wins the presidency in Mexico.
- The British government upgrades British East Africa from a protectorate to a colony and renames it as Kenya.
- Alphonse Capone migrates from New York City to Chicago.
- The Prohibition goes in effect in the United States of America.
- January: Indiana Jones begins his studies under Abner Ravenwood, and meets Marion.
- June 29: Henry Walton Jones, Sr. is aboard the steamer George S. Pilkington on his way to England.
- July 14: Henry Jones begins his research in Oxford, he eventually sees the Abergavenney manuscript.
- July 26: Henry visits Mochdref, Wales and asks about Taliesin in The Purple Dragon, engaging in drink contests. He was put to jail and Marcus Brody had to find his way there and pay the fee.
- July 31: Henry translates from Welsh the verses he learned in Mochdref.
- September 2: Henry is in the Abbey of Sankt-Gallen, Switzerland, and studies a manuscript of Hildegard of Bingen.
- September 29: Henry meets G. Codirolli in Bologna who hands him two of his findings related to the Grail: the testament of the Franciscan friar and an account of a Byzantine merchant.
- The Young Indiana Jones Chronicles – "Young Indiana Jones and the Mystery of the Blues" → Mystery of the Blues
- The Roaring Twenties
- The Young Indiana Jones Chronicles – "Young Indiana Jones and the Scandal of 1920" → The Scandal of 1920
- The Young Indiana Jones Chronicles – "Young Indiana Jones and the Hollywood Follies" → Hollywood Follies
- Grail Diary
- Who Are Those Guys? (Non-fiction source)
- Birth of a Nation (Non-fiction source)
- Sigmund Freud (Non-fiction source)
- The World of Indiana Jones
- Indiana Jones: The Ultimate Guide
- The Lost Journal of Indiana Jones
Notes and references