Scrooge had worked his way up the financial ladder from humble immigrant roots. Firstly, he took up a job polishing and shining boots, and was enraged when a ditchdigger paid him with an 1875 US dime, which was useless as currency in 19th century Glasgow. However, the coin inspired him to take a position as cabin boy on a Clyde cattle ship to the United States to make his fortune at the age of 13. In 1898, after many adventures he finally ended up in Klondike. There he found a golden rock the size of a goose's egg. The next year he had made his first $1,000,000 and bought the deed for Killmule Hill from Casey Coot, the son of Clinton Coot and grandson of Cornelius Coot.

He finally ended up in Duckburg in 1902. After some dramatic events where he faced both the Beagle Boys and president Roosevelt and his "Rough Riders" at the same time, he tore down the rest of the old fort Duckburg and raised his famous Money Bin at the same site. In the years to follow, Uncle Scrooge traveled all around the world in order to increase his fortune. During these and earlier travels he learned many different languages from all parts of the world. Meanwhile his family ran the Money Bin. When Scrooge finally returned to Duckburg, he found himself the richest duck in the world, rivaled only by Flintheart Glomgold, John D. Rockerduck and, less prominently, the maharaja of the fictional country Howdoyoustan (play on Hindustan). He had however changed. His newly developed personality - one that was a mix of hostility and crankiness made his own family leave him. 12 years later, he closed his empire down, but eventually returned to a public life 5 years later and started his business.
He keeps a portion of his wealth, money he has personally earned himself, in a massive Money Bin overlooking the city of Duckburg. In the short Scrooge McDuck and Money, he remarks to his nephews that this money is "just petty cash". In the Dutch and Italian version he regularly forces Donald and his nephews to polish the coins one by one in order to pay off Donald's debts—Scrooge will not even pay them much for this lengthy, tedious, hand-breaking work. As far as he is concerned, even 5 cents an hour is too much expenditure.

A shrewd businessduck and noted tightwad, he is fond of diving into his money, burrowing through it, swimming laps in it, spitting out coins that enter his mouth like water during these swimming sessions, and tossing coins into the air mirthfully only to let them fall upon his head — all without injury. He is also the richest member of The Billionaires Club of Duckburg, a society which includes the most successful businessmen of the world and allows them to keep connections with each other. Glomgold and Rockerduck are also influential members of the Club. His most famous prized possession is his Number One Dime.