What would 100000000 dollars in 1864 be worth today?

To estimate the value of $100,000,000 in 1864 in today's dollars, we can use historical inflation rates. Adjusted for inflation, that amount would be roughly equivalent to around $1.7 billion to $2.5 billion today, depending on the specific inflation measure used. This significant increase reflects the changes in purchasing power and economic growth over the past century and a half.