Two books that changed the science of astronomy and the world were __ by nicholas copernicus and__ by isaac newton

For Copernicus, I think it was On the Revolution of the Celestial Spheres. I think For Newton it was Philosophiæ Naturalis Principia Mathematica.

john maynard keynes developed new economic theories in response to the stock market crash of 1929. great depression of the 1930s. first and second world wars. economic boom of the 1950s.

union blockade

explanation:

the union blockade in the american civil war was a naval strategy by the united states to prevent the confederacy from trading.

the blockade was proclaimed by president abraham lincoln in april 1861, and required the monitoring of 3,500 miles (5,600 km) of atlantic and gulf coastline, including 12 major ports, notably new orleans and mobile. those blockade runners fast enough to evade the union navy could only carry a small fraction of the supplies needed. they were operated largely by british citizens, making use of neutral ports such as havana, nassau and bermuda. the union commissioned around 500 ships, which destroyed or captured about 1,500 blockade runners over the course of the war.