Paul allowed the of each letter to determine the style in which he wrote it. date
length
patron
purpose

Purpose
Explanation:
Depending on the purpose of your letter. It will always determine the style of the letter.
For example:
If I’m writing a letter to my friend about her vacation, then the letter should be friendly and questionable (since I’m curious of what she did during her vacation). If I’m writing a business letter to my boss, it should be professional or serious (since this is business)

The answer is william henry harrison pursued and defeated british forces retreating into canada.