What is associated with: at his death in april 1955 his brain was preserved his ashes scattered in the delaware river?

What is associated with: at his death in 1941 this pianist was president of polands exiled government? What is associated with: at his death in 1971 there were more than 1600 department stores bearing his name? What is associated with: at his death in 1995 this polio vaccine developer was working on another vaccine to prevent fu… Based on the clue 'at his death in 323 bc alexander the greats empire...', what is the answer? What is associated with: at his death in march 1848 he left a fortune estimated at 20 million acquired in the fur trade… What is associated with: at his death on october 20 1964 he had survived his presidency longer than any other president… What is associated with: at his death this oregon runner movie bio subject held every us record from 2000 to 10000 mete… What is associated with: at his first inauguaration on march 4 1861 he said the issue of civil war was not in his hands?