You Do Need power plug adapter while traveling from American Samoa to Sierra Leone.

Here is Why You Need An Adapter

The outlet and plug type used in Sierra Leone are D and G and in American Samoa are A, B, F and I. This is how they look like.

American Samoa

In American Samoa, outlets of type A, B, F and I are in use.

Type A

Type B

Type F

Type I

Sierra Leone

In Sierra Leone, outlets of type D and G are in use.

Type D

Type G