You Do Need power plug adapter while traveling from United States of America (US) USA to Gabon.

Here is Why You Need An Adapter

The outlet and plug type used in Gabon is C and in United States of America (US) USA are A and B. This is how they look like.

United States of America (US) USA

In United States of America (US) USA, outlets of type A and B are in use.

Type A

Type B

Gabon

In Gabon, outlets of type C are in use.

Type C