Flag of Germany
When Heinrich XI, Prince Reuss of Greiz was appointed by Joseph II, Holy Roman Emperor to rule the then-new Principality of Reuss-Greiz on 12 May 1778, the flag adopted by the "Fürstentum Reuß-Greiz" was the first-ever appearance of the black-red-gold tricolour in its modern arrangement in any sovereign state within what today comprises Germany – the Reuss elder line that ruled the principality used a flag whose proportions were close to a "nearly square"-shape 4:5 hoist/fly ratio, instead of the modern German flag's 3:5 figure.
Flags of the U.S. states and territories
Modern U.S. state flags date from the 1890s, when states wanted to have distinctive symbols at the 1893 World's Columbian Exposition in Chicago, Illinois. Most U.S. state flags were designed and adopted between 1893 and World War I.