Qual é a importância das fontes históricas, para compreendermos o passado?

nativists tried to get rid of the immigrants as they thought they were going to ruin the u.s.  

from the conditions of the working class in england by friedrich engels,the main idea is :

he is known for discovering   the fossil of a female hominin australopithecine   known as "lucy" in the afar triangle region of hadar, ethiopia.

hope this !

have a great day!

the  seven  days  battles  were  a series of seven battles over seven  days from june 25 to july 1, 1862, near richmond, virginia,  during  the american civil war. the  seven  days ended with mcclellan's army in relative safety next to the james river, having suffered almost 16,000 casualtiesduring  the retreat.