What did president theodore roosevelt do for public health?

During the 1750s, before the industrial revolution, why did most people see little of the world?

When the united states entered world war ii it affect the lives of americans in many ways people were asked to such as food oil and gas the government awesome cars to purchase a to the country financially during the war more more working in all industries during the war

What role did the alliance system play in preventing austria-hungary and serbia from coming to a compromise settlement?