The main factor that slowed construction of the central pacific railroad was a shortage of supplies, which had to be shipped around south america. intense summer heat that melted the railroad ties and tracks. scarcity of wood used for building railroad ties and trestles. conflicts with american indians who closed down the tracks.

The correct answer is a shortage of supplies, which had to be shipped around South America.

Although the government gave land to the railroad companies to accelerate the development of a transcontinental railroad, there was still a challenge of supplies which slowed down the construction

explanation: we can only guess at how our actions may be perceived in the future. doing something really big like killing lots of people, saving lots of people, affecting the lives of lots of people is a sure fire way of being remembered in historical records. we can also make a difference in the history records by being a small influence on something bigger, whether that is as a civil servant, scientist or artist.

of course you could argue that we all affect history just as tiny cogs in a   bigger machine.

if you mean how do people influence our opinions of things which have already happened, then simply by writing a book which looks at things form a different perspective and trying to convince people that this perspective is more accurate or truthful. people do it all the time i.e. richard the third was a terrible or was he? plenty would disagree, it's just that their views aren't the most widely known.n:

a drastic rise in oil prices ended decades of postwar.