What was inflation back in the 1900s?

Inflation was the same thing back then as it is now. Inflation rates were and are different in different countries, so the amount of inflation in each country is always different, depending on the solidity of the local currency. In Britain the inflation rate in 1900 was 4.5%. In the USA it was 16.9% but then fell to -2.4 the next year. Inflation rates in the US changed greatly from year to year and were often double-digit (but sometimes that was double-digit deflation)