Thanks for answering! He's from America.
I have pics of visiting, the wedding, some screenshots, lease signing, screenshots of Skype conversations, receipt of him paying for the wedding band. I figured I'd get letters from our parents, our friend in the States...maybe from his coworkers who know we're married and that we've been together since he came here last year. We're dumb and don't keep receipts or have money transfers though.
My worry is we don't have enough evidence for the first two years of our relationship. But writing it out now it seems we have a decent amount for now.