How many years are between 1850 and 1930?

Indus river civilization? Who began public health and sanitation systems? How is soap the yardstick of civilization? What is the most important development from the 1950's? What did western famers sold as their main cash crop? How man dress a 100 years ago? What did people on the frontier wear? Who pushed carmon wested? What was the English currency in 1605? What is the history of the letters on a phone dialing pad or rotary dial? What was a key goal of cathedral architecture in the late Middle Ages? What are the three ways that Charlemagne helped Europe? Who was credited for ending Spartacus's uprising? Who were the first people to inhabit the western hemisphere? What were two ways the crusades affect Europe? What century was 1266 CE? Did a female ever fight in the Roman army? Why did Tertullian condemn Greco-Roman philosophy and literature as dangerous for Christians? What factors facilitated the expansion of European society from 1450 to 1650 What was the motivation both for the individual European explorers and the states that supported them? Why is the great western cattle trail important to Americans?

How many years are between 1850 and 1930?