Explain the implications of language in the Treaty of Portsmouth

president thomas jefferson commissioned the expedition shortly after the louisiana purchase in 1803 to explore and to map the newly acquired territory, to find a practical route across the western half of the continent, and to establish an american presence in this territory before britain and other european powers

c) troops march forward in close formation against newer, more accurate weapons

a memoir is the correct answer

where is the passage

i cant solve it without knowing the passage