Along with quarantine, another one of Washington's methods for keeping his men healthy was with the use of inoculation. Washington, like others of the time period, was not intimately familiar with the exact mechanisms of the virus. However, he and others were able to realize that men who had previously contracted and subsequently recovered from smallpox were unlikely to become ill a second time. Thus, early on Washington recognized the strategic advantage of these individuals. During an outbreak in Boston, Washington sent troops made up only of men who had previously been infected with smallpox. With this, he was able to both protect his soldiers and take advantage of the vulnerability of Boston and its British inhabitants during the smallpox outbreak of March 1776.