It is time to get to work locating Edward Marden Sr. and Jr. in census records. But, before I do, I want to take a moment to remind my readers about the hazards associated with census records.
Census records are not proof of anything. The census taker may have made an error in recording information at the time he visited the family. The census taker may have made an error when he transferred his field data to the actual schedule he submitted to the government. The census taker may not have found anyone at home when he was in the neighborhood, so perhaps asked a neighbor to supply the information - there is no guarantee the neighbors knew what they were taking about. The person at home when the census taker visited may not have known the information being asked of them, they may have guessed! The census taker may have missed a family completely. This goes on and on - far too many ways for the information to be corrupted.
Prior to 1870, Native People are seldom found in census records - at least not labeled as "Indian". The census was originally established to determine how many people are paying taxes and how many elected representatives where needed for a particular region. It was about votes and taxes - Native People did not pay taxes and they did not have the right to vote, so there was no need to enumerate them in census records.