When we think of the term “filibuster,” the definition that springs to mind is the political one, a legislative tactic sometimes used in the United States Senate, the Parliament of the United Kingdom, and in many other Westminster-style legislatures. But it has a second, deprecated meaning, one related to military actions. In that sense, Wikipedia defines a filibuster as a person “who engages in a unauthorized military expedition into a foreign country to foment or support a revolution.” The classic example of a filibuster? Meet William Walker, pictured above.

Walker was born in Nashville, Tennessee in 1827. A savant of sorts, he graduated from college by age fourteen and went to Europe to study medicine. By his early twenties, Walker had a medical degree and was licensed to practice law in the States. But he wanted more. He wanted to be a king. So he did what anyone would do: he hired himself an army.

Walker’s dream was to create a slave ownership-friendly republic which, much like the Republic of Texas before it, would find itself invited to join the U.S. as a full state. At first, he attempted to take control of parts of Baja California in Mexico, and while he was briefly successful, the Mexican government managed to force him out. He returned to California, where he was put on trial for violating the Neutrality Act of 1794, but at the time, western Americans believed strongly in the notion of Manifest Destiny, and Walker was acquitted. He used his retained freedom to take another stab at his dream.

Opportunity knocked in 1855 when civil war broke out in Nicaragua. At the time — as there was no Panama Canal — Nicaragua was a major shipping transverse. Ships could enter Lake Nicaragua from the Atlantic and drop their cargoes on its western shore. From there, goods would be moved by stagecoach to the Pacific. Walker realized the importance of the country and, with the permission of one of the warring sides, entered the nation with 65 Americans as his army. When they arrived, Walker’s forces were joined by another 250 or so, a mix of men made up of American expats and local Nicaraguans. Walker’s side prevailed in the civil war, and in May of 1856 the United States recognized the Walker-backed government as the official one in charge of Nicaragua. Walker still needed the local leader to be his puppet regime, but in July, he ousted his ally in a fraudulent election.

As President of Nicaragua, Walker put his plan into action. He legalized slavery and made English the official language of the nation. He actively solicited Americans to immigrate to Nicaragua, positioning it as a staunch defender of slave ownership during a period when America was deeply divided on the issue. He even rebased the Nicaraguan currency to be indexed to the American dollar. But while this attracted a number of American southerners — and entrenched Walker as the leader of his new Nicaraguan empire — he provoked fear and anger among Nicaragua’s Central American neighbors. Thousands of troops, mostly from Honduras, overtook Walker and, upon his surrender, forcibly returned him to the United States in May of 1857.

Walker did not give up — but he probably should have. He returned to the region a few years later, and, quickly found himself unwelcome. He was turned over to the Honduran authorities who were, this time, not so willing to give him yet another chance to attempt a coup. On September 12, 1860, Walker was brought to the firing squad and executed.

Bonus fact : The term “filibuster” comes from the Spanish term “filibustero,” meaning “pirate.” In the legislative sense, the speaker is acting as a pirate, hijacking the legislative process; in Walker’s case, the etymology is probably closer to apt.

From the Archives: St. Patrick’s Battalion: Another group of Americans who made their way south in the 1800s to fight — but in this case, they fought against the United States.

Related: “Filibusters and Financiers: The Story of William Walker and his Associates” by William O. Scroggs. Not yet reviewed.