It helps them determine whether an assertion made by one source is likely to be true.
The main weapon that enabled the Europeans to conquer vast amounts of territories in distance lands was all the new sicknesses that were brought along with them. As stated in the book Guns, Germs and Steel written by <em>Jared Diamond</em> in 1997. The author explains that the Europeans had the technological advances of the era, such as gun powder, rifles, and cannons, but their most devastating weapon was the side effect of their presence, the presence of foreign bacteria to new populations.
The era of big business
This is because a lot of big businesses and industries starting to boom and suceed in the 1800s.