I GUESS IT SEEMED LIKE A GOOD IDEA AT THE TIME: On this day in 1855, William Walker, a 31-year-old, European-educated, physician-lawyer-journalist-duelist-adventurer from Tennessee, invaded Nicaragua with a tiny army of about 60 well-armed American “colonists.” Nicaragua had strategic importance in the pre-Panama Canal days. Most shipping between the oceans went up Nicaragua’s San Juan River into Lake Nicaragua and then briefly overland to the Pacific (or vice versa). Walker was a “make no little plans” kind of guy.  And he definitely liked a little excitement in life.

This was not Walker’s first rodeo. A few years earlier, he and 45 men had conquered Baja California—sort of. They managed to capture La Paz—then the capital of that sparsely populated territory—where he declared himself “President of the Republic of Lower California” and adopted the law of Louisiana to govern it. Not co-incidentally, that meant slavery was authorized. Walker was apparently hoping that his new nation would eventually enter the Union as a slave state. This made him popular with many Southerners and in particular with the Knights of the Golden Circle (a semi-secret society originally founded for that precise purpose–spreading slavery to Mexico and Central America and then annexing them to the U.S).

A few months later, without actually gaining control of Sonora, he declared Lower California to be a part of a larger “Republic of Sonora” and made himself President of that instead.

Suffice it to say the Mexican authorities were not amused. In about six months, they had run him back to the United States. The American authorities were not amused either. They put him on trial for violating the Neutrality Act of 1794. Fortunately for Walker, the jurors were amused. They took eight minutes to acquit him. (Yes, those were headier … or maybe just crazier days.)

In contrast to the Mexicans, Nicaraguans had mixed feelings about Walker’s invasion. The country was in the throes of a civil war at the time, and Walker allied himself with the side that seemed to be the underdog—the Liberal Party. Soon after arriving, his little army was joined by more Americans and foreigners as well as about 100 Nicaraguans. After a bloody conflict, Walker’s army prevailed, and eventually he declared himself President of Nicaragua and rescinded all laws banning slavery.  He also seized the assets of a prominent steamship company.

His glory days didn’t last long.

Here’s some advice just in case you’re considering invading a small country where large swaths of the population would like to see you dead: Don’t make it harder on yourself by annoying one of the richest men in the world. Walker pissed off Cornelius Vanderbilt, who owned the steamship company that Walker had essentially nationalized. Vanderbilt was not exactly known as the “go ahead and use me as doormat” type. He helped persuade Costa Rica and other neighboring countries to put an end to Walker’s grand ambitions.

Walker was lucky to get out of Nicaragua alive. His “presidency” lasted less than a year. Courtesy of the U.S. Navy, he was given a ride to New York, where he was briefly considered a bit of celebrity.

But like a moth to a flame, he was drawn back to Central America, where they obviously hadn’t forgotten him. The British Navy, which had its own interests in the region, delivered him to the authorities in Honduras in 1860, where he was tried, found guilty, and executed by firing squad. He was 36.

Think what you will about William Walker. But never let it be said that he lived a boring life.