How did people buy airline tickets before the internet?

In 1989, before no-frills airlines, online check-in, and price comparison sites had taken off, airline tickets were generally impenetrably complicated paper documents - laboriously hand written by a travel agent, with several sheets of carbon paper inserted between the leaves.

Explanation:

although world war i began in 1914, the united states did not join the war until 1917. the additional firepower, resources, and soldiers of the u.s. to tip the balance of the war in favor of the allies. remaining neutral. when war broke out in 1914, the united states had a policy of neutrality.