Final answer:
The US growth rate per capita since 1820 has fluctuated, with a slow growth rate at 1% being the weakest and a higher growth rate reaching 3% during strong economic times in the late 1990s and 2000s.
Step-by-step explanation:
The question asks about the US growth rate per capita since 1820. The data provided does not specifically cover the entire period from 1820 but offers insights into various growth rates experienced by the United States at different times. The slowest growth rate noted for the US, at 1% per year, occurred during its weakest years of productivity. A higher growth rate of 3% per year was observed during the booming economy of the late 1990s and into the 2000s. These rates help us understand the fluctuations in the US economy's growth over time, although a complete historical account from 1820 would require more detailed historical economic data.