Naturalists of Steno’s day were becoming convinced that matter was composed of different combinations of tiny “corpuscles”—what today we would call molecules. Steno argued that the corpuscles in the teeth were replaced bit by bit, by corpuscles of minerals. In this gradual process, the teeth didn’t lose their overall shape as they turned from tissue to stone.
Answer:
After World War II ended in 1945, Europe was divided into Western Europe and Eastern Europe by the Iron Curtain. Western Europe promoted capitalist democracies, and Eastern Europe came under the Communist influence of the Soviet Union
A biggie: the transcontinental railroad. Because it would economically improve wherever it was, both the North and the South competed for the railroad to be in their respective territory, evidenced by the Kansas-Nebraska Act and the Gadsen Purchase and induction of California as a free state in 1860.
In addition: people could get land cheap because it was abundant and might leave to start afresh economically.
There's other stuff I can't remember as clearly, but there's a little and I hope it helps :)
