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100 years of military history

  • 100 years of military history

    The world's mightiest military came from humble beginnings as colonial militias representative of the era’s free, white society. Men between the ages of 16 and 60 were recruited to colonial militia service from all walks of life, including shopkeepers, tutors, small farmers, and smiths. Left out of that recruitment were college enrollees, slaves, most free blacks, and clergy—and, in Virginia, Catholics. Men who were recruited were asked to make inarguably heavy sacrifices during their service, which included operations against Native Americans and supplementing Red Coats in border skirmishes with neighboring European colonies. The colonial militia’s first overseas foray came in 1741 and ended in abject disaster when 4,000 American reinforcements joined an attempted British invasion of Cartagena, Colombia, then a Spanish possession. The invasion failed miserably and only around 600 American volunteers returned home alive from the expedition.

    In the lead up to the Revolutionary War, the American militia was prepared to step up in case of emergency for the paid, trained soldiers in the Continental Army (established by the Continental Congress in 1775), although the militia ultimately provided far more soldiers for that effort than the fledgling army. The British Regulars, or Red Coats, assumed this growing military was made up of laborers, criminals, and other struggling members of society, and ill-equipped to handle the brutality of war. That misguided perspective—largely brought about because Britain itself enlisted soldiers from its own, lowest classes—along with a big boost from the French, ultimately cost Britain the colonies during the Revolutionary War.

    The U.S. Armed Forces over the last century have played major roles in two world wars, a wide variety of civil conflicts, and dozens of ongoing military campaigns. These efforts have made significant impacts on how our government makes decisions that may affect domestic and foreign affairs. The military itself has undergone a few structural changes in that time as well, including adding new divisions and permitting women and LGBTQ+ people to serve in all military branches.

    In honor of Veterans Day, Stacker looked at information from the Defense Manpower Data Center, the U.S. Census historical population tables, and the St. Louis Federal Reserve to see how the military has changed over the years. By comparing data sets (last updated 2019) we were able to determine the percentage of Americans enlisted in the military and the number of Americans in each military branch every year from 1917 to 2019.

    You may also like: 50 ways the military has changed in the last 50 years

    [Pictured: Selected senior American commanders of the European theater of World War II]

  • 1917: U.S. enters WWI

    - Army strength: 421,467 people
    - Navy strength: 194,617 people
    - Marine Corps strength: 27,749 people
    - Air Force strength: Not yet formed
    - Total strength: 643,833 people
    - Percent of population enlisted: 0.62%

    Congress granted President Woodrow Wilson's request for a declaration of war against Germany on April 6, 1917, officially entering the United States into World War I. The Army expanded dramatically in the next 18 months, from 200,000 men in December 1916 to 3,685,000 troops in 1918—2 million of whom were stationed in France to serve in Gen. John Pershing's American Expeditionary Force.

    [Pictured: President Woodrow Wilson delivering his war message in the Senate Chamber, July 2, 1917]

  • 1918: Meuse-Argonne Offensive

    - Army strength: 2,395,742 people
    - Navy strength: 448,606 people
    - Marine Corps strength: 52,819 people
    - Air Force strength: Not yet formed
    - Total strength: 2,897,167 people
    - Percent of population enlisted: 2.81%

    Thousands of American troops joined forces in September 1918 with the allied intervention force at Archangel in response to the Bolshevik revolution in Russia. American soldiers engaged in several major battles that year as part of World War I, including the Meuse-Argonne Offensive from Sept. 26 through Nov. 11, which involved more than 1 million American soldiers (26,000 of whom died in battle and 120,000 casualties overall). The offensive was the largest of the American Expeditionary Forces in World War I and is largely credited with ushering in the end of the war on Nov. 11, 1918.

    [Pictured: U.S. Marines during the Meuse-Argonne Campaign]

  • 1919: Treaty of Versailles

    - Army strength: 851,624 people
    - Navy strength: 272,144 people
    - Marine Corps strength: 48,834 people
    - Air Force strength: Not yet formed
    - Total strength: 1,172,602 people
    - Percent of population enlisted: 1.12%

    Following the conclusion of WWI, the Treaty of Versailles was signed June 28, 1919, in the Palace of Versailles, France. The peace document included signatures from allied powers and Germany, and went into effect the following year with redrawn German boundaries and an outline of required reparations from the country. After signing the treaty on behalf of the United States and presenting his Fourteen Points that included the formation of the League of Nations, U.S. President Woodrow Wilson returned home only to find an obstinate Senate had voted against the treaty—twice.

    [Pictured: The signing of the Treaty of Versailles on June 28, 1919]

  • 1920: National Defense Act amended

    - Army strength: 204,292 people
    - Navy strength: 121,845 people
    - Marine Corps strength: 17,165 people
    - Air Force strength: Not yet formed
    - Total strength: 343,302 people
    - Percent of population enlisted: 0.32%

    Congress in 1920 passed an amendment to the National Defense Act, which rejected the concept of an expandable “Regular Army” and called for the U.S. Army to have three main divisions: the standing Regular Army, National Guard, and Organized Reserves.

    [Pictured: Officers of the 8th Surveillance Squadron, McAllen Field, Texas, 1920]

  • 1921: The Unknown Soldier

    - Army strength: 230,725 people
    - Navy strength: 132,827 people
    - Marine Corps strength: 22,990 people
    - Air Force strength: Not yet formed
    - Total strength: 386,542 people
    - Percent of population enlisted: 0.36%

    Congress approved the burial of an unidentified body from World War I on March 4, 1921, at Arlington National Cemetery. The "Unknown Soldier" commemorates the 116,516 American soldiers killed in World War I, many of whose bodies were never identified.

    [Pictured: Unknown Soldier is laid to rest in Arlington National Cemetery on Nov. 11, 1921]

  • 1922: Washington Naval Treaty

    - Army strength: 148,763 people
    - Navy strength: 100,211 people
    - Marine Corps strength: 21,233 people
    - Air Force strength: Not yet formed
    - Total strength: 270,207 people
    - Percent of population enlisted: 0.25%

    The Washington Naval Treaty was signed by the United States, United Kingdom, Japan, France, and Italy on Feb. 6, 1922. The document, also known as the Five-Power Treaty, was drafted to prevent an arms race following World War I.

    [Pictured: American Legion Weekly highlighting the plight of unemployed American veterans in 1922]

  • 1923: Warlordism

    - Army strength: 133,243 people
    - Navy strength: 94,094 people
    - Marine Corps strength: 19,694 people
    - Air Force strength: Not yet formed
    - Total strength: 247,031 people
    - Percent of population enlisted: 0.22%

    American soldiers spent part of 1923 in China, helping to control unrest that ensued amidst warlordism—the era from 1923 to 1928 marked by the dilemma of Beiyang Army military factions vying for control of China. The period of time represents a division of control spread out across the country.

    [Pictured: Two Airco DH-4B biplanes perform the first ever mid-air refueling on June 27, 1923]

  • 1924: First U.S. occupation of Dominican Republic ends

    - Army strength: 142,673 people
    - Navy strength: 98,184 people
    - Marine Corps strength: 20,332 people
    - Air Force strength: Not yet formed
    - Total strength: 261,189 people
    - Percent of population enlisted: 0.23%

    The U.S. Navy invaded the Dominican Republic in 1916, taking over the army, police, and several vital locations as Desiderio Arias, the Dominican Republic’s secretary of war, was forced out of Santo Domingo. The occupation lasted through 1924, when waning public support following World War I and significant opposition internationally and among Dominicans inspired the U.S. to turn policing authority over to the Guardia Nacional. Back home, the Immigration Act of 1924 allowed immigration visas for 2% of the number of people from each nationality in the U.S. according to the 1890 census. The act neglected to include visas for any immigrants from Asia, making it illegal for them to cross the U.S. shoreline and enter in spite of continued unrest overseas.

    [Pictured: First Regiment Band, U.S. Marine Corps, Santo Domingo, Dominican Republic]

  • 1925: Riots in Shanghai

    - Army strength: 137,048 people
    - Navy strength: 95,230 people
    - Marine Corps strength: 19,478 people
    - Air Force strength: Not yet formed
    - Total strength: 251,756 people
    - Percent of population enlisted: 0.22%

    Continued unrest from Chinese factions competing for political power in Shanghai erupted into riots. American troops were brought in to protect the public—and the terms of the Shanghai International Settlement during one of the most pivotal moments in Chinese history.

    [Pictured: Arrival of Dutch marines from the SS Sumatra in Shanghai]

  • 1926: U.S. squashes Nicaraguan coup d’état

    - Army strength: 134,938 people
    - Navy strength: 93,304 people
    - Marine Corps strength: 19,154 people
    - Air Force strength: Not yet formed
    - Total strength: 247,396 people
    - Percent of population enlisted: 0.21%

    The 1912 to 1933 U.S. occupation of Nicaragua was part of the “Banana Wars,” a period of various military interventions, massacres, and actions by the U.S. throughout the Caribbean and Central America following the Spanish-American War’s 1898 conclusion and the 1934 establishment of the Good Neighbor Policy. U.S. military presence in Nicaragua chiefly functioned to protect American business interests (soldiers kept unrest at a minimum on plantations the U.S. had a stake in and break apart any uprisings) and thwart any other would-be occupiers from constructing the Nicaraguan Canal. In 1925, the election of conservative President Carlos Solorzano helped form a coalition government. Thirteen years into their occupation, the U.S. Marines left Nicara. But by October of that year, Nicaraguan Gen. Emiliano Chamorro Vargas staged a successful coup d’état against Solorzano. Chamorro became president, but the U.S. did not recognize his rule; after a liberal revolt, the U.S. military in January 1926 sent gun-boats and troops back into the country and forced Vargas’ resignation.

    [Pictured: Harry Truman talking to an unidentified soldier at Fort Riley, Kansas, July 1926]