Complex sentence: Some, including Jackson, argued that preemptive action against the Ordinance of Secession before it was ratified was unwise: the Ordinance had not yet been presented to the citizens of Virginia for a vote, and would not be until May 23.
Split into simpler sentences: Some, including Jackson, argued that preemptive action against the Ordinance of Secession before it was ratified was unwise. The Ordinance of Secession would not be presented to the citizens of Virginia for a vote until May 23.