There were many groups because the Empire was located at the crossroads of the continents. That's why its culture was influenced by both western cultures such as the Greek and Roman ones, but also by eastern ones such as Turks, Persians, Arabs, Egyptians, and similar.
The US respond to Villa's actions by The Pershing expedition
<u>Explanation:</u>
Since 1910 the Mexican revolution was causing utter destruction. In 1916, a leader named “Pancho” Villa crossed the Mexico border entered U.S and burnt down the Columbus town. It was actually an act of revenge that he wanted to take as Venustiano Carranza was declared as President of Mexico surpassing him.
Villa raided and took materials of war as he was desperate to take over the ammunition's and create a stir among the American government. This raid of Columbus definitely drew the attraction of the U.S. to wage a war against Mexico. The U.S responded by sending troops led by General Pershing in search of Villa which was unsuccessful.
The Stamp Act of 1765.
The stamp act was an insanely high tax placed on the American colonists by the British empire, and Americans had absolutely no say in it.
Here you have a vast definition :) May it be helpful.