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

Here is Why You Need An Adapter

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

French Guiana

In French Guiana, outlets of type C, D and E are in use.

Type C

Type D

Type E

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