Two most important factors were the development of industry and industrialization, and the slave trade. People started accumulating large amounts of wealth due to these two and started investing them in businesses, both personal and by other people. This led to the development of capitalism not only in Europe, but other places too.
17th amendment..... this is correct just took it
: <span>Only about 2.8 million were drafted under the Selective Service System
All males aged 21 to 30 were required to register for military service for a service period of 12 months. As of mid-November 1917, all registrants were placed in one of five new classifications. Men in Class I were the first to be drafte and men in lower classifications were deferred. Dependency deferments for registrants who were fathers or husbands were especially widespread.[9] The age limit was later raised in August 1918 to a maximum age of 45. The military draft was discontinued in 1920
</span>
