1806 Congress authorizes survey of Cumberland Road

Congress authorizes surveying to begin for the construction of the Cumberland Road, which sped the way for thousands of Americans heading west.

Four years earlier, Congress had recognized the importance of building a network of national roads to facilitate western immigration. The 1803 act that admitted Ohio into the Union included a provision setting aside money from the sale of public lands to use in "laying out, opening, and making roads." By 1806, enough funds had accumulated to begin surveying a proposed national road from Cumberland, Maryland, through the Appalachian Mountains to Wheeling, Virginia, on the Ohio River.

The task of surveying the route for the new national road went to the Army's Corps of Engineers, setting an important precedent for the military's involvement in building transportation routes that would be used for non-military purposes. The Corps of Engineers also built the road once construction began in 1811. Progress was slow, and the Corps did not complete the 130-mile road until 1818. Its value, though, became apparent well before it was completed. Stagecoaches, heavy freight wagons, and droves of stock animals soon crowded the route in numbers far surpassing those expected. The Corps even had to maintain and repair older sections of the road before the entire route was completed.

The Cumberland Road proved such a success that Congress agreed to continue extending it westward. By 1850, this National Road, as it came to be called, reached all the way to Indianapolis. By that time, mid-western excitement over the National Road was fading in favor of a fever for canal building. The Cumberland-National Road, however, set the precedent for further government involvement in road building. The resulting network of roads greatly facilitated American expansion into western territory, and parts of the route blazed for the Cumberland Road are still followed to this day by interstate and state highways.

1951 Rosenbergs convicted of espionage

In one of the most sensational trials in American history, Julius and Ethel Rosenberg are convicted of espionage for their role in passing atomic secrets to the Soviets during and after World War II. The husband and wife were later sentenced to death and were executed in 1953.

The conviction of the Rosenbergs was the climax of a fast-paced series of events that were set in motion with the arrest of British physicist Klaus Fuchs in Great Britain in February 1950. British authorities, with assistance from the U.S. Federal Bureau of Investigation, gathered evidence that Fuchs, who worked on developing the atomic bomb both in England and the United States during World War II, had passed top-secret information to the Soviet Union. Fuchs almost immediately confessed his role and began a series of accusations.

Fuchs confessed that American Harry Gold had served as a courier for the Soviet agents to whom Fuchs passed along his information. American authorities captured Gold, who thereupon pointed the finger at David Greenglass, a young man who worked at the laboratory where the atomic bomb had been developed. Gold claimed Greenglass was even more heavily involved in spying than Fuchs. Upon his arrest, Greenglass readily confessed and then accused his sister and brother-in-law, Ethel and Julius Rosenberg, of being the spies who controlled the entire operation. Both Ethel and Julius had strong leftist leanings and had been heavily involved in labor and political issues in the United States during the late-1930s and 1940s. Julius was arrested in July and Ethel in August 1950.

By present-day standards, the trial was remarkably fast. It began on March 6, and the jury had convicted both of conspiracy to commit espionage by March 29. The Rosenbergs were not helped by a defense that many at the time, and since, have labeled incompetent. More harmful, however, was the testimony of Greenglass and Gold. Greenglass declared that Julius Rosenberg had set up a meeting during which Greenglass passed the plans for the atomic bomb to Gold. Gold supported Greenglass's accusation and admitted that he then passed the plans along to a Soviet agent. This testimony sealed Julius's fate, and although there was little evidence directly tying Ethel to the crime, prosecutors claimed that she was the brain behind the whole scheme. The jury found both guilty. A few days later, the Rosenbergs were sentenced to death. They were executed on June 19, 1953 in Sing Sing Prison in New York. Both maintained their innocence to the end.

The Rosenberg case garnered worldwide attention. Their supporters claimed they were being made scapegoats to the Cold War hysteria that was sweeping America. The French writer and philosopher Jean-Paul Sartre called their execution a "legal lynching." Others pointed out that even if the Rosenbergs did pass secrets along to the Soviets during World War II, Russia had been an ally, not an enemy, of the United States at the time. Those who supported the verdict insisted that the couple got what they deserved for endangering national security by giving top-secret information on a devastating weapon to communists.

The unmanned U.S. space probe Mariner 10, launched by NASA in November 1973, becomes the first spacecraft to visit the planet Mercury, sending back close-up images of a celestial body usually obscured because of its proximity to the sun.

Mariner 10 had visited the planet Venus eight weeks before but only for the purpose of using Venus' gravity to whip it toward the closest planet to the sun. In three flybys of Mercury between 1974 and 1975, the NASA spacecraft took detailed images of the planet and succeeded in mapping about 35 percent of its heavily cratered, moonlike surface.

Mercury is the second smallest planet in the solar system and completes its solar orbit in only 88 earth days. Data sent back by Mariner 10 discounted a previously held theory that the planet does not spin on its axis; in fact, the planet has a very slow rotational period that stretches over 58 earth days. Mercury is a waterless, airless world that alternately bakes and freezes as it slowly rotates. Highly inhospitable, Mercury's surface temperature varies from 800 degrees Fahrenheit when facing the sun to -279 degrees when facing away. The planet has no known satellites. At the dawn of the 21^st century, Mariner 10 is the only human-created spacecraft to have visited Mercury