tldr, "Pay your debts son!"
book review by "the official Historian of the Federal Reserve System"
snip
"Now, we get to one point on which I disagree with the author. Edwards clearly believes the United States federal government defaulted on its debts. The Supreme Court equivocated, but generally seemed to think that the United States did not default, and I agree with the Supreme Court. Let me explain.
Merriam-Webster’s dictionary defines a default as either a (1) failure to do something required by duty or law or (2) a failure to pay financial debts. The United States Supreme Court decision in the gold cases indicated that the federal government defaulted in the first sense.
.....
The Supreme Court ruled that the federal government did not default in the second sense. "