Career
He represented the Belfast South constituency as an Independent Unionist at the Westminster parliament from 1902 to 1910. In 1901, Trew was sentenced to twelve months" hard labour after he incited an anti-Catholic riot, and Sloan took over his Sunday afternoon speeches on the steps of Belfast Customs House. Trew"s imprisonment had increased interest, and Sloan was a superior speaker and organiser, and managed to secure his election at the Belfast South by-election, 1902, against the official unionist candidate.
In 1903, Sloan founded the Independent Orange Order.