What is the historical significance of cast iron?

When did France get out of World War 2? What systems of trade was most widely used in both ancient river civilizations and ancient Native American civilizations? How did john marshall serving in the Virginia legislature when Virginia planters refused to pay their debts to English merchants help factor his political philosophy? What led to the first generation of individual American debt? What did Christopher Columbus use to explore? Why did the Framers of the Constitution decide that the US needed a new govt? Did a poor person in Rome have a fresh water supply? How do you address a military officer in a proper memorandum or letter? How did reformers want to change education? What were the pitching stats for baseball player Bobby Castillo playing for the Los Angeles Dodgers in 1978? What us navy ships are still commisioned but not on active service? When and where did baseball player Rick Ferrell die? Why did the President have the power to purchase the Louisiana purchase? Who has 5 World Series rings with 5 different teams? What was the Pilgrims attitude when they first arrived at Cape Cod? What year did Hatshepsut become pharaoh? What baseball player went 0 for 59 then got 9 straight base hits? What was Ottoman Empire years at height? Who was the first to grow Tobacco in the new world? In 1968 a wedding linked together one of the world's most glamorous women with one of the world's wealthiest men who was the lucky couple?