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

Here is Why You Need An Adapter

The outlet and plug type used in American Samoa are A, B, F and I and in Mali are C and E. This is how they look like.

Mali

In Mali, outlets of type C and E are in use.

Type C

Type E

American Samoa

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

Type A

Type B

Type F

Type I