I am doing the same thing at this time, for state of Maryland he

http://sos.maryland.gov/Certifications/Pages/default.aspx

call the office first, they will give you all the details

I am trying to get my SS card translated to chinese so I have to 

1 have the doc notarized in your own county

2 have the doc certified by your own county circuit court

3 go to state office - see link above for marylander

4. go to chinese consulate for chinese copy or see step 5

5 for chinese embassy in DC you need 1 more step, send doc to US office of authentication in DC. link below

https://travel.state.gov/content/travel/en/legal-considerations/judicial/authentication-of-documents/office-of-authentications.html