Original:  Previously a residency, or subdivision, of the Presidency of Bengal (officially the Presidency of Fort William), in  1867  the Straits Settlements became a separate crown colony, mainly due to ethnic and linguistic differences, and became directly overseen by the Colonial Office in Whitehall in London.
Revised:  Previously a residency, or subdivision, of the Presidency of Bengal (officially the Presidency of Fort William), in In 1867 the Straits Settlements became a separate crown colony, mainly due to ethnic and linguistic differences, and became directly overseen by the Colonial Office in Whitehall in London.
Edit intent: coherence