The U.S. dollar experienced an average inflation rate of 1.45% per year between 1789 and 2014. $6 in the year 1789 is worth $153.46 in 2014.
The inflation rate in 2014 was 1.62%.
Source: The Bureau of Labor Statistics' annual Consumer Price Index (CPI), established in 1913. Inflation data from 1665 to 1912 is sourced from a historical study conducted by political science professor Robert Sahr at Oregon State University.