Short answers, pulled from the story.
The earliest known camel called Protylopus lived 40 to 50 million years ago during the Eocene epoch. It roamed open woodlands where South Dakota now stands and was about the size of a rabbit.
A dromedary camel can drink as seldom as once every ten days even under very hot conditions. They sustain speeds of up to forty kilometers per hour over longer distances while losing only 1.3 liters of fluid intake daily compared to twenty to forty liters for other livestock.
Bactrian camels were likely domesticated in central Asia around 2500 BC. A study from 2016 suggested initial domestication occurred in the southeast Arabian Peninsula while Martin Heide's 2010 work concluded humans had domesticated the Bactrian camel by at least the middle of the third millennium east of the Zagros Mountains.
The United States Army established the U.S. Camel Corps stationed in California during the 19th century. One may still see stables at the Benicia Arsenal where they now serve as the Benicia Historical Museum.
The wild Bactrian camel is critically endangered and numbers approximately nine hundred fifty individuals. These wild camels inhabit the Gobi and Taklamakan Deserts in China and Mongolia.