thomas jefferson was alarmed by the fierce debate over __the missouri warning americans about its threat to national unity.
in 1820, jefferson wrote a “letter to john holmes” outlining his belief that establishing a “line drawn for slavery” will damage the country’s unity.
in 1917 world war i began. america tried to stay neutral but couldn't due to these two main reasons:
germans continuing to practice unrestricted submarine warfare and sinking frieghters and tankers without warning- breaching the “rules” of war.
germany getting caught sending a telegram trying to become allied with mexico to gain access to united states borders and to provide mexico with funds to gain back land lost to the united states (nm, tx, az).