Looking at https://usafacts.org/data/topics/economy/economic-indicators/gdp/gross-domestic-product/?adjustment=Inflation it looks like the USA’s GDP in 1944 was $3.1T in 2019 dollars, so the Manhattan project (even spread over four years) couldn’t be anywhere near $3.3T.
Looking at https://usafacts.org/data/topics/economy/economic-indicators/gdp/gross-domestic-product/?adjustment=Inflation it looks like the USA’s GDP in 1944 was $3.1T in 2019 dollars, so the Manhattan project (even spread over four years) couldn’t be anywhere near $3.3T.