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I asked my internship supervisor at a federal government agency if he/she would write me a letter of rec that I could include with select jobs apps (I recently graduated). The Supervisor would have very good things to say about me. Is this a good idea? If an employer received an employment application that included a "To whom it may concern" LOR from (for example) an attorney at the DOJ Federal Tort Claims Act Division, would the employer roll their eyes or actually take it seriously?

Input would be especially helpful (in order of helpfullness) if you (1) are an employer/recruiter, (2) are a law grad and have used an LOR like this before, or (3) you know someone who has done this.

(4) would be you are just opinionated and have some cogent input for me.

Nobody?

I've used that type of letter before and I've had interviewers mention it was helpful. I never used it for firms, though, so I'm not sure if a government rec would be helpful w/ them (unless the work is directly related).