Last week, President Biden issued a new order requiring all federal employees, as well as all employees at the Veterans Administration, to receive the COVID-19 vaccine or undergo a strict testing and masking program. Gov. Gavin Newsom of California and Gov. Andrew Cuomo of New York have issued similar orders for their states. While these mandates are the first vaccine requirements for COVID-19, the United States has a long history of protecting the nation’s health through vaccines.

It began with George Washington in 1777, less than one year after the U.S. declared independence from Great Britain. During the Revolutionary War, smallpox was the biggest threat to the Continental Army, threatening to inflict far more damage on the troops than the British forces. While 18th-century Americans didn’t fully understand the science behind smallpox, they knew that it seemed to break out in crowded areas — like big cities or military camps — and killed one-third of all who contracted the disease.

Doctors in Massachusetts first deployed a crude vaccine in the 1720s, and leading figures, including Thomas Jefferson, Benjamin Franklin and Martha Washington, received the inoculation. To administer the vaccine, doctors lanced a pustule of an infected patient and then sliced the same knife under the skin of a healthy individual. The vaccinated patient usually contracted a milder case of smallpox, rendering them immunized against potentially deadlier strains in the future. Despite the life-saving benefits of the vaccine, many officials distrusted the science and blamed the inoculation for spreading the disease. Under this assumption, the Continental Congress had banned inoculations in 1776.

By February of the following year, however, Washington was desperate. Smallpox was attacking his soldiers, and given the close quarters at camp, there was little he could do to prevent its spread. As regiments from the south planned to march north, he took drastic action to prevent them from catching the disease once they reached Philadelphia. After catching smallpox as a teenager and living with the scars on his face to prove it, Washington knew how deadly the disease could be.

On Feb. 5, Washington wrote John Hancock, president of Congress, sharing his plans to “innoculate all the Troops now here, that have not had it,” as well as his intention to “innoculate the Recuits as fast as they come in to Philadelphia [sic].” The general assured Hancock that the army would lose no time while the recruits were in quarantine, as they had to wait while “their cloathing Arms and accoutrements are getting ready” anyway.

Washington also alerted the nearby state conventions, urging them to inoculate their troops before sending them to winter quarters. He also reminded them: “We intend for the present to keep the Matter as much a Secret as possible, and I would Advise you to do the same.” If the British discovered that the Continental Army was recovering from the inoculation, they would certainly seize the opportunity to strike.