You need to get this properly valued! I don't want to get your hopes up for something I am not an expert in, however, I think your Lewis Boston Nat card is worth between $2000 and $4000.
Does your card look like this one:
Irving Lewis Supposedly played for the Boston Braves (known as the Rustlers in 1911)
Irving's card is one of three very rare cards in the set (the others being Louis Lowdermilk of the Cardinals and Ward Miller of the Cubs).
There is nothing on the internet that I could find about Irving's career which may account for the rarity of the card.
I hope it is good news to you that the card is worth this amount, whatever you decide to do with it.