Polio vaccine trials begin On this day in 1954, the Salk polio vaccine field trials, involving 1.8 million children, begin at the Franklin Sherman Elementary School in McLean, Virginia. Children in the United States, Canada and Finland participated in the trials, which used for the first time the now-standard double-blind method, whereby neither the patient nor attending doctor knew if the inoculation was the vaccine or a placebo. On April 12, 1955, researchers announced the vaccine was safe and effective and it quickly became a standard part of childhood immunizations in America. In the ensuing decades, polio vaccines would all but wipe out the highly contagious disease in the Western Hemisphere. Polio, known officially as poliomyelitis, is an infectious disease that has existed since ancient times and is caused by a virus. It occurs most commonly in children and can result in paralysis. The disease reached epidemic proportions throughout the first half of the 20th century. During the 1940s and 1950s, polio was associated with the iron lung, a large metal tank designed to help polio victims suffering from respiratory paralysis breathe. President Franklin Roosevelt was diagnosed with polio in 1921 at the age of 39 and was left paralyzed from the waist down and forced to use leg braces and a wheelchair for the rest of his life. In 1938, Roosevelt helped found the National Foundation for Infantile Paralysis, later renamed the March of Dimes. The organization was responsible for funding much of the research concerning the disease, including the Salk vaccine trials. The man behind the original vaccine was New York-born physician and epidemiologist Jonas Salk (1914-95). Salk’s work on an anti-influenza vaccine in the 1940s, while at the University of Michigan School of Public Health, led him, in 1952 at the University of Pittsburgh, to develop the inactivated polio vaccine (IPV), based on a killed-virus strain of the disease. The 1954 field trials that followed, the largest in U.S. history at the time, were led by Salk’s former University of Michigan colleague, Dr. Thomas Francis, Jr. In the late 1950s, Polish-born physician and virologist Albert Sabin (1906-1993) tested an oral polio vaccine (OPV) he had created from a weakened live virus. The vaccine, easier to administer and cheaper to produce than Salk’s, became available for use in America in the early 1960s and eventually replaced Salk’s as the vaccine of choice in most countries. Today, polio has been eliminated throughout much of the world due to the vaccine; however, there is still no cure for the disease and it persists in a small number of countries in Africa and Asia. 1798 Mountain man James Beckwourth is born James Beckwourth, one of only a handful of early mountain men to emerge from the system of slavery, is born in Fredericksburg, Virginia. The exact year of Beckwourth’s birth is in dispute. Some historians suggest it may have been 1800 rather than 1798. The uncertainty arises both from Beckwourth’s notorious reputation for exaggerating and rewriting his own history, as well as the humble circumstances of his birth. The child of a white plantation owner and a black woman who was probably his slave, Beckwourth was born into a society that paid little notice to children born of black mothers. During his childhood, Beckwourth may have been a slave. However, by the time he reached adulthood in St. Louis, Missouri, his master had apparently manumitted him and he was regarded as a free black man. In 1824, he joined William Ashley’s third and most arduous fur-trapping expedition to the Rocky Mountains. Beckwourth received a crash course in the dangers of mountain life, just barely managing to avoid death by freezing, starvation, and Indian attacks. Despite the risks, Beckwourth enjoyed being a mountain man, and he spent the next several years as a free trapper. Trapping in the Powder River country of Wyoming, Beckwourth began to forge a close alliance with the Crow Indians. Sometime between 1826-1828, he abandoned American society altogether and joined the Crow people. The Crow had long been friendly with trappers, and they apparently welcomed Beckwourth into their society. Beckwourth learned the Crow language, customs, and ways of living, and he married at least two Crow women and fathered several children. Beckwourth later claimed that he became a powerful chief among the Crow, though historians have questioned whether this was another of his exaggerations. In the mid-1830s, Beckwourth left his adopted home with the Crow and joined the Missouri volunteer military force as a scout. He saw action in the Seminole War in Florida, fighting under General Zachary Taylor. Beckwourth left the army in 1840 and spent the next decade wandering around the West, occasionally making some quick cash by stealing horses. Eventually settling near Denver, Colorado, Beckwourth continued to work periodically as a civilian scout for military parties. In this capacity, Beckwourth had a role in the infamous Sand Creek Massacre of 1864, but how much Beckwourth knew about or participated in that inexcusable massacre of Indians is still disputed. Not long after the Sand Creek Massacre, Beckwourth again abandoned Anglo-American society and returned to the Crow tribe. As with his birth, the details of Beckwourth’s death are uncertain. Some accounts say he died in 1866 among his adopted people, and they laid him to rest in Crow fashion on a tree platform; others indicate he may have died near Denver in 1867. 1865 Lincoln assassin John Wilkes Booth dies John Wilkes Booth is killed when Union soldiers track him down to a Virginiafarm 12 days after he assassinated President Abraham Lincoln. Twenty-six-year-old Booth was one of the most famous actors in the country when he shot Lincoln during a performance at Ford’s Theater in Washington, D.C., on the night of April 14. Booth was a Maryland native and a strong supporter of the Confederacy. As the war entered its final stages, Booth hatched a conspiracy to kidnap the president. He enlisted the aid of several associates, but the opportunity never presented itself. After the surrender of Robert E. Lee’s Confederate army at Appomattox Court House, Virginia, on April 9, Booth changed the plan to a simultaneous assassination of Lincoln, Vice President Andrew Johnson, and Secretary of State William Seward. Only Lincoln was actually killed, however. Seward was stabbed by Lewis Paine but survived, while the man assigned to kill Johnson did not carry out his assignment. After shooting Lincoln, Booth jumped to the stage below Lincoln’s box seat. He landed hard, breaking his leg, before escaping to a waiting horse behind the theater. Many in the audience recognized Booth, so the army was soon hot on his trail. Booth and his accomplice, David Herold, made their way across the Anacostia River and headed toward southern Maryland. The pair stopped at Dr. Samuel Mudd’s home, and Mudd treated Booth’s leg. This earned Mudd a life sentence in prison when he was implicated as part of the conspiracy, but the sentence was later commuted. Booth found refuge for several days at the home of Thomas A. Jones, a Confederate agent, before securing a boat to row across the Potomac to Virginia. After receiving aid from several Confederate sympathizers, Booth’s luck finally ran out. The countryside was swarming with military units looking for Booth, although few shared information since there was a $20,000 reward. While staying at the farm of Richard Garrett, Federal troops arrived on their search but soon rode on. The unsuspecting Garrett allowed his suspicious guests to sleep in his barn, but he instructed his son to lock the barn from the outside to prevent the strangers from stealing his horses. A tip led the Union soldiers back to the Garrett farm, where they discovered Booth and Herold in the barn. Herold came out, but Booth refused. The building was set on fire to flush Booth, but he was shot while still inside. He lived for three hours before gazing at his hands, muttering “Useless, useless,” as he died.