Complex sentence: Brigham cites the newspaper's publisher as Samuel Magill from the first issue located from December 11,1813 vol.1 no.4 and Brigham cites that Magill established the newspaper on November 20,1813.
Split into simpler sentences: Brigham cites the newspaper's publisher as Samuel Magill from the first issue located which is from December 11,1813 vol.1 no.4. From that same edition Brigham also cites that Magill established the newspaper on November 20,1813.