Upon landing off the Saint Lawrence River, Honeyman's unit was almost immediately put into action against the French during the Siege of Louisbourg which ended after 48 days on July 26, 1758.

The success of the siege cleared the way for the British expedition led by General Wolfe to take New France at Quebec City the following summer and which culminated in the Battle of the Plains of Abraham on September 13, 1759.

While it ended with a British victory, Wolfe was fatally shot and Honeyman was among those who carried the General down the heights to his shelter, where he died.

He took up his trade as a butcher and weaver and he married the former Mary Henry, an Irish girl from Coleraine at the First Presbyterian Church in Philadelphia on September 22, 1764.

He was instructed to continue trading as much as possible behind the American lines in Griggstown and, if necessary, to flee to Trenton on the pretext of the danger posed to his family due to his double-dealing.

Fortunately, his family were saved from certain harm by a signed letter from Washington guaranteeing its safety, but nevertheless calling Honeyman "a notorious Tory".

Having amassed enough information, he arranged to be captured by the Continental forces, who had been ordered to watch for him and bring him straight to Washington unharmed.

After receiving the information Honeyman had gathered, Washington ordered the guards to feed the "Tory" and lock him up in a small hut used as a prison.

Even though the Hessians had been on heightened alert for the past two weeks, they believed Honeyman's story and so felt confident enough to relax security on December 26.

On the night of December 25–26, 1776, with 2,400 troops, Washington made the well known crossing of the Delaware River from Pennsylvania to New Jersey north of Trenton.

"[2] Supporters argue that the lack of direct evidence merely points to the excellent job Honeyman, and Washington, did concealing his actions as a spy.

John C. Van Dyke records that Honeyman "had always been considered a poor man, and his neighbors were much surprised when he died leaving about twelve thousand dollars.