Modern Americans can join the military and go to war without too much fuss, since the U.S. still needs people for ongoing fights in Syria, Iraq, Afghanistan, and other hotspots around the world.
But our forefathers didn't always have a place to go if they got the martial itch. Sometimes, they really wanted to join a war that the American people didn't want to get involved in.
That's when truly bold Americans would just join another country's military and get to work.
1. Polish 7th Air Escadrille
As a victor of World War I, Poland grew in size, gained a border with Russia, and quickly found itself at war with the communist Bolsheviks. American volunteers were allowed to form the Polish 7th Air Escadrille and the aviation unit engaged in fierce ground attacks against Russian cavalry from 1919 to 1920.
The unit started with eight pilots but conducted more than 400 combat sorties. American Capt. Merian C. Cooper was awarded Poland's highest military honors, the Virtui Militari, for his service there after he was shot down and escaped from a Soviet prisoner of war camp.
2. The gendarmeries and national guards of Haiti, the Dominican Republic, and Nicaragua
In the early 1900s, Marines were sent to Caribbean nations to protect American business interests and to help shore up governments friendly to the U.S. The Marines who were dispatched to the islands often ended up holding ranks in both the U.S. military and the local forces at once. For instance, then Maj. Smedley Butler was the commandant of the Haitian Gendarmerie and then Cpl. Lewis B. "Chesty" Puller was a second lieutenant in the Gendarmerie.
3. Eagle Squadrons
Americans who wanted to take the fight to Nazi Germany before Pearl Harbor had few legal options, but some lied about their citizenship and risked exile from America to join the Royal Air Force in 1939 and 1940. Eight Americans took part in the 1940 Battle of Britain that saw the RAF narrowly defeat attempts by Luftwaffe to open the British Isles to invasion.
Dozens more Americans arrived after the Battle of Britain and helped the U.K. hold the line until America's entry into the war after the attack on Pearl Harbor.
4. The Lincoln and Washington Battalions
When a fascist military coup failed to topple the Spanish government in 1936, a bloody civil war erupted that saw approximately 40,000 international volunteers, including 2,800 Americans, fight on behalf of the Spanish Republic. The American volunteers formed the "Lincoln" and "Washington" battalions, that were part of a larger, international brigade known as the Abraham Lincoln Brigade.
Unfortunately, the fighting went badly for the American volunteers. Nearly one-third of them died in Spain and the Republic was overthrown by Fascist Gen. Francisco Franco.
5. The Flying Tigers
The Flying Tigers of World War II were a group of American pilots and ground crew who President Franklin D. Roosevelt secretly authorized to go to China and help that country fight the Japanese invasion. Despite the presidential authorization, the Americans had to resign their military positions and travel under assumed identities.
Once in country, they crewed Curtiss P-40 Warhawks and devastated the Japanese aviators. The Flying Tigers started with 99 planes and destroyed 297 enemy birds. The unit boasted 20 ace pilots and helped China keep Japan occupied until the U.S. could start operations in the Pacific.
6. The Lafayette flying corps
Soon after the onset of World War I in 1914, American volunteers began flying over the skies of France and serving on the ground against the Central Powers. One of the most famous American units in the war was the Lafayette Escadrille — a flying squadron named for the French hero of the American Revolution, Gilbert du Motier, the Marquis de Lafayette.
The pilots' exploits were covered in U.S. newspapers and they became heroes at home and in France. Thirty-eight U.S. pilots would eventually serve in the unit and it earned 57 aerial kills before it was turned over to American control in February 1918.