Here is one of my favourite stories from the war, how the American side at Fort Mackinac weren't given the courtesy of a tiny detail like a war being declared.
Capture of Fort Mackinac
The United States Secretary of War William Eustis, who was apparently preoccupied with financial economies, had sent no communications to Hanks for several months. He sent word of the declaration of war on 18 June to the commanders in the northwest by ordinary rate post. The Postmaster at Cleveland, Ohio, realised the importance of the news and hired an express rider to take it to Brigadier General William Hull who was advancing on Detroit, but it was too late to save both Hull and Hanks from being taken by surprise by the outbreak of hostilities.[5]
Though he was unaware of events elsewhere, Hanks had heard rumours of unusual activity at St. Joseph Island. He sent a fur trader named Michael Dousman, who held a commission as an officer in the militia, to investigate. Dousman's boat was captured by the advancing British force, and Dousman apparently quickly changed sides.[1]
Having learned from Dousman that the U.S. forces were unaware of the outbreak of war, Robert's force landed at a settlement subsequently named British Landing on the north end of the island, 2 miles (3.2 km) away from the fort, early on the morning of 17 July. They quietly removed the village's inhabitants from their homes, dragged a 6-pounder cannon through the woods to a ridge above the fort, and fired a single round before sending a message under a flag of truce, demanding the U.S. forces surrender.[4]
Hanks's force was surprised and was already at a tactical disadvantage. The flag of truce had been accompanied by three of the villagers, who greatly exaggerated the number of Indians in Roberts's force.[6] Fearing a massacre by the Indians, Hanks capitulated without a fight. The United States garrison was taken prisoner but was released on giving their parole not to fight for the remainder of the war.