Hethe number of significantly increased after the civil war connecting the united states and creating a national market.
a. railroads

b. steel industry

c. oil production

d. john d. rockefeller

e. andrew carnegie

f. monopoly

g. telegraph

h. telephone

i. electric light bulb

j. ellis island

k. angel island

l. labor unions

m. american federation of labor

n. plains indians

o. transcontinental railroad

p. “muckraker”

q. ida tarbell

r. upton sinclair

s. the jungle

t. jacob riis

u. jane addams

v. jim crow laws

w. plessy v. ferguson

x. naacp

y. 17th amendment

z. conservation movement

ad. spanish american war

bc. imperialism

bd. philippine-american war

be. roosevelt corollary

cd. panama canal

ce. theodore roosevelt

these are the option but only one of them are correct for this answer