The US reached the height of its economic prowess - a height never achieved by any other nation, anywhere, with a middle class of unimaginable size - under the watchful eye of the Fed. That is a definition of "broke" that most countries would kill for.
A medicine for a very rare disease is a type of monopoly that could last a long time. Quick example of very expensive medicines that don't appear to have any competition: The World's Most Expensive Drugs Competitors may or may not be able to produce an alternative due to the sheer complications of the disease or the costs in undertaking the task.