Why did it take so long for U. S. troops to enter combat?

Thousands of men refused to participate in the military draft

It took longer than expected for the U. S. to produce a sufficient amount of weapons

General Pershing sent the troops to camps in eastern France for more training

In the World war I The American army was under command of General Pershing. They fought together with the French, British, Canadian an Australian army as the allied forces against the German invasion of France. General Pershing insisted that the American troops first needed to be trained well before joining the frontline. The troops arrived in France in June 1917 but only in May 1918 the battle was won.

Question: Why did it take so long for U. S. troops to enter combat?

Answer: General Pershing sent the troops to camps in eastern France for more training