Bill Morgan takes his girlfriend out to eat; she orders such a huge dinner that he remonstrates with her, saying, "My name is Morgan, but it ain't J. P." Other examples of her profligacy follow; at last Morgan gives up on her
John Pierpont Morgan (1837-1913), mortgage banker, was probably the most powerful financier in American history; he controlled railroads, steel mills and the largest bank on Wall Street. The size of his enterprises is demonstrated by the fact that his bank actually financed the Federal Reserve Board in its early years.
Morgan also (at the request of Theodore Roosevelt) managed the stock market problem which led to the Panic of 1907. Using his own money and money he pried out of other bankers, he managed to stabilize the financial system, though the resulting recession hurt ordinary people badly. - PJS, RBW
This has the hallmarks of a vaudeville song. - PJS
And the New Lost City Ramblers version heightens this impression with an additional chorus. - RBW
We should note that this is NOT the same as the Mitchell Trio song "My Name Is Morgan," though that was doubtless suggested by this piece. - RBW