Complex sentence: Manchester became the headquarters of the Anti-Corn Law League from 1839, in order to campaign against the Corn Laws and so both reduce food prices for its poorer inhabitants and increase manufactured-goods competitiveness abroad, and Manchester Liberalism grew out of this movement.
Split into simpler sentences: Manchester became the headquarters of the Anti-Corn Law League from 1839. The League campaigned against the Corn Laws to reduce food prices and increase the competitiveness of manufactured goods abroad, and Manchester Liberalism grew out of this movement.