Since I'm supposed to be painting a bathroom today, I decided to play around with your genealogy. Mary's family name was Bužonas, and Martin and Mary apparently entered the US in 1890 or 91. Mary, and probably Martin, was from a tiny village called Gluosninkai in Alytus County.
I know you are very concerned about whether they were "from" Russia or "from" Lithuania. Perhaps this map will clarify the reason for you that a question such as that is really not relevant. https://commons.wikimedia.org/wiki/Atlas_of_Lithuania#/media/File:Rzeczpospolita_Rozbiory_3.png
Basically the borders were extremely fluid. You might wake up one day and find yourself under Russian rule, though you went to bed last night living in part of Poland or Lithuania. It's far more relevant to know what town/village one came from.