Ameliorate the Proclamation Line of 1763

Directions: grammatically correct the sentence(s) below, in red. There are 3 missing commas. There are 2 sentences. There are a few misused words.

after the conclusion of the french and indian war the British Empire began two tighten control over it's colonies the proclamation line which closed down colonial expansion westward was the first measure to affect all thirteen colonies.

Video Link
suggested answer: 
After the conclusion of the French and Indian War, the British Empire began to tighten control over its colonies. The Proclamation Line, which closed down colonial expansion westward, was the first measure to affect all thirteen colonies.