Civil Rights
Movements, leaders, victories and the continuing fight for equality.
Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
Mansa Musa was the ruler of the Mali Empire in West Africa. Details recorded here should be sourced; unknown information is left blank.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
Asdic was the British version of sonar developed at the end of World War I based on the work of French physicist Paul Langevin and Russian engineer M. Constantin Chilowsky. The system was developed as a means to detect and locate submarines by their reflection of sound waves. By the start of World War II in 1939, most British destroyers and smaller vessels were fitted with it in a variety of different sets.
Bold (also called Bolde, a term derived from kobold) was a German sonar decoy, used by U-boats during the Second World War from 1942 onwards. It consisted of a metal canister about 10 cm (3.9 in) in diameter filled with calcium hydride. It was launched by an ejector system colloquially referred to as Pillenwerfer (English: "pill thrower"). When mixed with seawater, the calcium hydride produced large quantities of hydrogen, which bubbled out of the container, creating a false sonar target. A valve opened and closed, holding the device at a depth of about 30 m (98 ft). The device lasted 20 to 25 minutes. It replicated the echo of an Asdic-sonar submarine contact. The Royal Navy called it SBT (Submarine Bubble Target).
Naval trawlers are vessels built along the lines of a fishing trawler but fitted out for naval purposes; they were widely used during the First and Second World Wars. Some, known in the Royal Navy as "Admiralty trawlers", were purpose-built to naval specifications; others were adapted from civilian use. Fishing trawlers were particularly suited for many naval requirements because they were robust vessels designed to work heavy trawls in all types of weather, and had large clear working decks. A minesweeper could be created by replacing the trawl with a mine sweep. Adding depth charge racks on the deck, ASDIC sonar below, and a 3-inch (76 mm) or 4-inch (102 mm) gun in the bow equipped the trawler for anti-submarine duties.
The early phase of the Battle of the Atlantic during which Kriegsmarine U-boats enjoyed significant success against Allied warships and merchantmen was referred to by U-boat crews as the Happy Time (German: Die glückliche Zeit), and later the First Happy Time, after a second successful period was encountered. It started in July 1940, almost immediately after the Fall of France, which brought the German U-boat fleet closer to the British shipping lanes in the Atlantic. From July 1940 to the end of October, 282 Allied ships were sunk off the north-west approaches to Ireland for a loss of 1,489,795 GRT of merchant shipping. The reason for this successful Axis period was the British lack of radar and huff-duff-equipped ships which meant that the U-boats were very hard to detect when they made nighttime surface attacks – ASDIC (sonar) could only detect submerged U-boats. When it ended is a matter of interpretation, with some sources claiming October 1940 and others extending it to April 1941, after the Germans lost three prominent U-boat commanders: Günther Prien, Joachim Schepke, and Otto Kretschmer.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Brown v. Board of Education in 1954.