The Second Class Passenger was in Jamrach's employ at the time and knew Barnum well.

He said the thing began in this way.

One morning Barnum and Jamrach were in Jamrach's little private snuggery back of the wilderness of caged monkeys and snakes and other commonplaces of Jamrach's stock in trade, refreshing themselves after an arduous stroke of business, Jamrach with something orthodox, Barnum with something heterodox--for Barnum was a teetotaler.

The stroke of business was in the elephant line.

Jamrach had contracted to deliver to Barnum in New York 18 elephants for $360,000 in time for the next season's opening.
Then it occurred to Mr.Barnum that he needed a "card" He suggested Jumbo.