over 700 members arrived at the Maine shore opposite the island intending to seize Campobello from the British. Royal Navy officer Charles Hastings Doyle, stationed at Halifax, Nova Scotia, responded decisively. On 17 April 1866, he left Halifax with several warships carrying over 700 British soldiers and proceeded to Passamaquoddy Bay, where the Fenian force was concentrated. This show of force by Doyle discouraged the Fenians, and they dispersed. The invasion reinforced the idea of protection for New Brunswick by joining with the British North American colonies of Nova Scotia, and the United Province of Canada, formerly Upper Canada (now Ontario) and Lower Canada (Quebec), to form the Dominion of Canada. Canada West After the Campobello raid, the "Presidential faction" led by Fenian founders James Stephens and John O'Mahony focused more on fundraising for rebels in Ireland. The more militant "Senate Faction" led by William R. Roberts believed that even a marginally successful invasion of the Province of Canada or other parts of British North America would provide them with leverage in their efforts. After the failure of the April attempt to raid New Brunswick, which had been blessed by O'Mahony, the Senate Faction implemented their own plan for invading Canada. Drafted by the senate "Secretary for War" General T. W. Sweeny, a distinguished former Union Army officer, the plan called for multiple invasions at points in Canada West (now southern Ontario) and Canada East (now southern Quebec) intended to cut Canada West off from Canada East and possible British reinforcements from there. Key to the plan was a diversionary attack at Fort Erie from Buffalo, New York, meant to draw troops away from Toronto in a feigned strike at the nearby Welland Canal system. This was the only Fenian attack, other than the Quebec raid several days later, that was launched in June 1866. About 1000 to 1300 Fenians crossed the Niagara River in the first 14 hours of June 1 under Colonel John O'Neill. Sabotaged by Fenians in its crew, the U.S. Navy's side-wheel gunboat did not begin intercepting Fenian reinforcements until 2:15 p.m.—14 hours after Owen Starr's advance party had crossed the river ahead of O'Neill's main force. Once the USS Michigan was deployed, O'Neill's force in the Niagara Region was cut off from further supplies and reinforcements. After assembling with other units from Canada and travelling all night, Canadian troops advanced into a well-laid ambush by