Why did James Fenimore Cooper add the name Fenimore to his name?

Question

At age 35 he legally added the name Fenimore to his name. What was the significance of this name to him, where did it come from and why did he think it important to add it to his professional name?

Answer 1

In April 1826 the New York legislature passed an act changing his surname of Cooper to Fenimore-Cooper.

This was done at the request of his grandmother, who did not want her ancestral surname to die out.

Initially Cooper made a point of writing out the new name in its hyphenated form but he eventually abandoned the practice.  Thus Fenimore came to appear as though it were a middle name rather than part of his surname.

Answer 2

It was his mothers Maiden Name