The 1900 census of Pitcairn, Allegheny County shows Matthew McIndoe, born Nov 1863, and Margarett, born April 1865, both in Scotland. They also immigrated in 1890 and were married 10 years.
This may interest you. This same Matthew was naturalized and in his federal papers it says he was from Paisley, Scotland and immigrated in March 1890 and landed in NY. The only thing I could find was a Matthew McIndo 25 from Scotland who landed in NY on the S.S. Britannic on Oct 17, 1890. I could not find Margaret under Waddell or Mcindoe.