1863: john d. rockefeller partners with maurice b. clark and samuel
andrews to open his first oil refinery.
1871: j. p. morgan becomes a partner in the banking firm drexel, morgan &
co.
1875: andrew carnegie uses money from earlier investments to open his first
steel mill.
1882: rockefeller forms the standard oil trust, which controls most u. s. oil
production.
1889: morgan merges several electricity companies to found general electric.
1892: striking workers at carnegie's mill in homestead, pennsylvania, clash
with hired security forces.
1895: morgan takes over drexel and restructures it to become j. p. morgan &
co.
1899: carnegie combines several steel mills that he has purchased into
carnegie steel.
1901: morgan buys out carnegie for $480 million and forms u. s. steel.
1914: the united mine workers strike at a rockefeller-owned coal mine in
ludlow, colorado, ends in a massacre.

the information in the timeline most directly relates to the development of
which movement?

a. temperance reformers
b. farmers' cooperatives
c. settlement houses
d. labor unions