Answer:
Medina
The time period under the leadership of the Four Caliphs is called the Rashidun Caliphate by historians. The Rashidun Caliphate lasted for 30 years from 632 CE to 661 CE. It was followed by the Umayyad Caliphate. The city of Medina served as the first capital of the Caliphate.
1935= Dust Storm
1931= Hoover Dam
1929= Stock
1938= Fight
1930= Banks Shut Down