Here's one take, and fairly accurate.
Coffee popularity has roots back to the Revolutionary War
As we all know, the US used to be a British Colony. And then there was a giant tea party where we tossed a bunch of tea overboard to protest taxes. But, what most people aren’t too aware of are the events that occurred afterwards.
John Adams declared tea a "traitor's drink"
In a letter from John Adams to his wife, he stated, "Tea must be universally renounced and I must be weaned, and the sooner the better." From this point on there was an unofficial boycott on tea in the (then) British Colonies. People united and vowed to only serve coffee in their homes. Soon this show of solidarity spread throughout the Colonies and people began to associate coffee with the Revolution. It even got to the point where people viewed drinking tea as a betrayal to the Colonies.
Why it was such a popular movement
Back in the late 1700s, tea was quintessentially British. The King and Queen drank it, all the royalty drank it and the entire population was fanatical about tea. On the business side, the East India Company (which was British) ruled the tea trade and the British were in the process of setting up their own tea farms in Sri Lanka (formerly Ceylon) and India. Tea was so closely associated with Britain that to boycott tea was to boycott British culture.
Tea was eventually phased out
The Boston Tea Party occurred in 1773. The end of the Revolutionary War was in 1783. This means that the Colonists (and soon to be Americans) had boycotted tea for roughly 10 years. It was over these 10 years that people developed a taste for coffee and once people started to drink coffee every day, there was no going back.
Plus, brits destroy their tea with milk and sugar anyway, making it more of a slightly tea flavored milk and sugar drink than anything recognizable as decent...