Does a civil union change my H1B status or green card app?

[A_colorado]

Hi everyone,

I'm working on a H1B visa and applying for a green card through my job at a university.

My partner and I are planning to get a civil union (in Colorado). Will this affect my current H1B visa, or my green card application that's already in progress? I doubt it as civil unions are not federally recognized but I would love some reassurance!

Thanks so much in advance for any replies.

[inadmissible]

USCIS will not recognize your civil union as a marriage for the purpose of derivative or spousal benefits, but will recognize it as restraining your freedom to marry. To me, that seems like the worst of both worlds, so I trust you know what you are doing

[A_colorado]

USCIS will ... recognize it as restraining your freedom to marry.

Thanks for your reply. I don't understand this point and would really appreciate if you could clarify it.
Why would a civil union restrain my freedom to marry my partner at a later date? And would this affect my visa or green card application?