This question is about inflation statistics.
The highest U.S. inflation rate ever recorded was 29.78% in 1778. As a new country, it experienced rapid and intense changes that affected the economy and everyone who participated in it.
Likewise, since the U.S. introduced the CPI, the highest inflation rate recorded was 19.66% in 1917. This spike was caused by WWI.
Finally, the highest inflation rate seen within the past 50 years occurred in 1980, when inflation reached 14.6%. This event occurred just before Ronald Reagan took office in 1981.