What happened on January 18, 1919? Where?

What was the overall impact of eli whitneys introduction of interchangeable parts?

After nine states had ratified the constitution by mid-1788, other states quickly followed. all thirteen states had to obey it. it became law in the united states. none of the states had to obey it.

Which of these rose during the great depression? a migration b consumerism c membership in the republican party d employment