I'm currently entering my senior year of college and am beginning to apply for full time positions after graduation.
For the past 1.5 years I've worked part time during the school year and full time during the summers for a mid-large size firm. One of the supervisors who I worked closely with wrote my a one page letter of reference at my request. This supervisor used to be a high up department head for a major government regulatory agency (he has a Wikipedia page and is extremely well known by those within the industry). The reference letter he wrote me is extremely positive and highlights much of the specific work we have done together over the past 1.5 years. It's about a page long.
I obviously want to highlight that relationship and present future employers with the letter as I feel that it would certainly help me in my application. The issue that i'm having is that the majority of applications don't ask for a reference letter. Should I send this reference letter to employers even if it has not been asked for?
For example I am actually applying to work in the government agency he used to head. Obviously I feel that his recommendation would carry a lot of weight but the application for that position doesn't ask for a reference letter and doesn't seem to expect it. How can I include the letter in these types of applications or should I simply leave it out unless asked?
I've already highlighted that we had a close working relationship in my resume and talked about some of the work we did together but would like to showcase his perspective if possible.