July 1: Colombo Plan operations commence. - Judy Garland opens the first of 14 concerts in Dublin, Ireland at the Theatre Royal.

July 5: William Shockley, John Bardeen, and Walter Brattain announce the invention of the junction transistor.

July 10: Korean War: Armistice negotiations begin at Kaesong.

July 13: The Great Flood of 1951 reaches its highest point in Northeast Kansas, culminating in the greatest flood damage to date in the Midwestern United States. - MGM's Technicolor film version of Show Boat, starring Kathryn Grayson, Ava Gardner, and Howard Keel, premieres at Radio City Music Hall in New York City. The musical brings overnight fame to bass-baritone William Warfield (who sings Ol' Man River in the film).

July 14: In Joplin, Missouri, the George Washington Carver National Monument becomes the first United States National Monument to honor an African American.

July 16: King Leopold III of Belgium abdicates in favour of his son Baudouin.

July 17: King Baudouin takes the oath as king of Belgium.

July 20: King Abdullah I of Jordan is assassinated by a Palestinian while attending Friday prayers in Jerusalem.

July 26: Walt Disney's 13th animated film, Alice in Wonderland, premieres in London, United Kingdom.

July 30: David Lean's Oliver Twist is finally shown in the United States, after 10 minutes of supposedly anti-Semitic references and closeups of Alec Guinness as Fagin are cut. It will not be shown uncut in the U.S. until 1970. (source: Wikipedia)