The Home Insurance Building, completed in 1884 in Chicago, Illinois, is generally noted as the world's first skyscraper. It was the first tall building, (originally 138 feet and 10 stories) to be supported by a fireproof metal frame. The building weighed only one-third as much as a comparable stone building, (supported by its walls) allowing it to climb higher without crushing its base. In 1890, two additional floors were added, making the building 190 feet in total. It was demolished in 1931. The Field Building, a 45-storey, 535-foot skyscraper completed in 1934 now occupies the site at 135 South LaSalle St.

In 1951, the year of Bobby Thomson's shot-heard-round-the-world home run at The Polo Grounds, (which ended a tie-breaking three-game playoff with the crosstown Brooklyn Dodgers and sent the Giants to the World Series) major league baseball had sixteen teams. Three were in New York, two in Boston, two in Chicago, two in Philadelphia, and two were in St. Louis. The remaining cities were Pittsburgh, Cleveland, Detroit, Cincinnati, and Washington.

Six of the sixteen teams have since relocated.

The Boston Braves moved to Milwaukee for the 1953 season. The Braves then moved to Atlanta in 1966.

The St. Louis Browns became the Baltimore Orioles in 1954.

The Philadelphia Athletics moved to Kansas City for the 1955 season before moving on to Oakland in 1968.

In 1958, two of New York’s iconic teams, together moved out of their aging homes, and with the promise of new stadiums with plenty of parking, public money, and a vast untapped market, headed west. The New York Giants and Brooklyn Dodgers moved to San Francisco and Los Angeles.

The Washington Senators moved to Minneapolis and became the Minnesota Twins in 1961.

The ‘51 Giants lost the World Series to the Yankees four games to two.

On May 4, 1970, 29 members of the Ohio National Guard fired 67 rounds into a crowd of student protesters, killing four and wounding nine at Kent State University. For several days students had been protesting recent events (specifically President Richard Nixon's April 30 announcement of the start of the Cambodian Campaign) in the ongoing Vietnam War.

Killed were Jeffrey Duane Miller, age 20, shot from 81 meters; Allison D Krause, age 19, shot from 105 meters; William Knox Schroeder, age 19, shot from 116 meters; Sandra Lee, age 20, shot from 120 meters. All four were students in good standing at Kent State.

No criminal charges resulted from the killings. The State of Ohio settled a civil case including financial retribution to the families of the victims.

None of the victims killed or wounded by the government-issued M1 rifles was armed.