We were installing a new dishwasher and this is what we found .  What's that color?  I think it is the original flooring!  Linoleum was invented in 1863 so it was around in 1917.  (However, after further research, I think that this was added over the heart pine flooring perhaps in the late 20s or early 30s.)

With a little ammonia and water  it cleaned up pretty good.  There are some water stains and an imprint from the dishwasher legs.  There is 1/4 inch wood and linoleum tiles above the original flooring (judging from the edges of the opening).  Then a rug was installed by the previous owners back in the 80s. We are planning on taking up the floor in the kitchen this winter and install stone tile unless the original wood flooring is in good condition.  I doubt we can restore this linoleum but I'll leave it under the dishwasher for the next person to discover.  I'll frame and hang any sections I can salvage.  It's art!