Identify a new invention or technology, and describe how it cities grow.

The telephone made communication easier.

Mass-produced steel allowed cities to build skyscrapers.

The elevator made skyscrapers more practical.

Electricity made working in factories easier.

Subways, elevated trains, and streetcars made it easer to move around the city.

frederick william of brandenburg-prussia trained his son, frederick, to be a hardy soldier. but frederick disliked rifle shooting and horseback riding. unlike his father, he was interested in french literature. he enjoyed poetry and music and, like some others of the enlightenment, he scoffed at religion. his father thought him soft, frivolous and unmindful of his duties. and when frederick refused to put his signature on a right to succession, for a few moments his father strangled him.

united states reinforcements contributed greatly to three allied victories in france at: cantigny (first major american battle), argonne (the largest in the united states military history, involving 1.2 million american soldiers), and château-thierry (one of the first actions under general pershing).