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

Here is Why You Need An Adapter

The outlet and plug type used in Latvia are C and F 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

Latvia

In Latvia, outlets of type C and F are in use.

Type C

Type F