The phrase “Jumping Jehoshaphat!” wasn’t clearly “coined” by one specific person in everyday speech, but the earliest known written use comes from a 19th-century novel.

Earliest recorded use

The first documented appearance is in 1866 in

the adventure novel The Headless Horseman by Thomas Mayne Reid. In that book the phrase appears as “Jumpin’ Geehosofat!”, used as a colorful exclamation.

Another early variation appeared around the same time in Paul Peabody (1865) by Percy Bolingbroke St John, which used the longer oath “By the shaking, jumping ghost of Jehoshaphat.”

Why “Jehoshaphat”?

• Jehoshaphat was a biblical king of Judah mentioned in the Old Testament.

• In the 1800s people often created “minced oaths”—milder substitutes for religious expressions like “Jesus!” or “Jehovah!” to avoid blasphemy.

• “Jumping Jehoshaphat!” became a dramatic but harmless way to say “Good heavens!” or “Wow!”.

How it became famous

The expression later spread through comic strips, western stories, and cartoons,

especially characters like Yosemite Sam in Looney Tunes who shouted it frequently.

✅ In short:

• First recorded: 1866

• Source: The Headless Horseman by Thomas Mayne Reid

• Meaning: a mild exclamation of surprise