Whiteboard
Whiteboards became commercially available in the early 1960s, but did not become widely used until 30 years later. Early whiteboards needed to be wiped with a damp cloth and markers had a tendency to leave marks behind, even after erasing the board. Dry-erase markers for whiteboards were invented in 1975.
Banjo
Although Robert McAlpin Williamson is the first documented white banjoist, in the 1830s Sweeney became the first white performer to play the banjo on stage. His version of the instrument replaced the gourd with a drum-like sound box and included four full-length strings alongside a short fifth string. This new banjo was at first tuned d'Gdf♯a, though by the 1890s, this had been transposed up to g'cgbd'. Banjos were introduced in Britain by Sweeney's group, the American Virginia Minstrels, in the 1840s, and became very popular in music halls.