Complex sentence: Marshall ruled that because Burr had not committed an act of war, he could not be found guilty (see Ex parte Bollman); the First Amendment guaranteed Burr the right to voice opposition to the government.
Split into simpler sentences: Marshall ruled that because Burr had not committed an act of war, he could not be found guilty (see Ex parte Bollman). Because the First Amendment guaranteed Burr the right to voice opposition to the government.