What did research conducted in 2009 at carnegie university mellon predict?

Examine these two paintings that depict famous events from american history. the image on the left, painted in 1940, shows the signing of the u.s. constitution in 1787. the image on the right, painted in 1836, shows the american victory at the battle of yorktown in 1781.which of these paintings should be considered a secondary source?

What was the result on the u.s. economy because of the major changes in atlantic shipping prior to and during the war of 1812?

How did patrick henry‘s word i am not a virginian but an american symbolism importance of the first continental congress