Interesting - I found this quantitative historical study [0] showing that while a civil war does significantly increase the likelihood of inflation, only 36% of countries analyzed which had a civil war between 1975-1999 ended up in an inflationary crisis. And with the USD having such a strong foundation, I would expect the risk to be significantly lower.
I am speculating wildly but I would expect the exact opposite due to different actors trying to destabilize the US to the point of no recovery in such an event.