PHOTO: Alan L. Hart, shown in 1943, grew up in Albany, Oregon (across the river from Corvallis, Oregon State University) as Alberta Lucille Hart and is considered to be an early example of an FTM or female-to-male. Early gay historians controversially categorized Hart as a lesbian instead of transgendered or other category. Even earlier, many people thought that women would dress as men to obtain male privileges common before the 1960's women's liberation movement started. (See previous posts Oregon FTM doctor's 1925 marriage and Baker case recalled by Portland gay newspaper (7/23/15), Albany, Oregon FTM Alan Hart 1890-1962 (9/3/11), Jonathan Ned Katz gay history pioneer (3/6/10) and Alan L. Hart (Wikipedia))
The 1970 marriage of Jack Baker and Michael McConnell, which was the basis of the first U.S. Supreme Court case on same-sex marriage (Baker v. Nelson 1972), is the first known historical example of an intentional same-sex marriage between two people who both considered themselves to be congruent with their assigned gender identity and biological sex. (See previous post Baker on gay marriage in 1972 vs. 2015 reaction to Supreme Court ruling (7/17/15))
However, if you include transgender individuals, there are much earlier historical examples of same-sex marriages, such as the one documented in a blog post by Jim Burroway, "TODAY IN HISTORY: A Same-Sex Marriage in Nevada: 1877," boxturtlebulletin.com posted Sep. 28, 2015, which references an earlier guest post on the same blog site by Homer Thiel, "A Same-Sex Marriage In 1877," boxturtlebulletin.com posted Aug. 15, 2015.
In my opinion, the same-sex marriages of transgendered people are probably more common than thought, because such marriages can be done silently "on-the-down-low" -- the couples will have birth certificates that comply with various State laws that assume marriage is between people of the opposite biological sex.
In my experience, no FTM I know has ever said they adopted a male role to obtain male privileges -- all of them said that they were born that way and their acting male seemed to be more natural to them than dressing up as a girl. It is unfortunate that most people assume FTM's are motivated by male privileges, which was the assumption in the case documented above, because assuming this limits the understanding of FTMs and gender. Every FTM I know has said that virtually no man will fully accept their maleness and in their experience, many men will react to it with anger and feel threatened by it. I guess the heterosexual male ego is fragile as Freud thought a century ago!
For an example of females working in male roles see previous posts Gender bending OSU student recruits women into science and engineering (7/12/14) and Kim Kraemer auto mechanic 1980 (11/7/09) about how a female mechanic was worthy of a newspaper story decades ago. (Of course, today I still don't see too many female auto mechanics or engineers even though they have increased in number!)