Who is Jonnie Keath from Moccasin Trail and what is their importance?

Jim's younger brother. Jonnie is determined to take his younger brother and sister on to Oregon and to claim land there, but he is only seventeen and cannot claim land on his own. He sends a letter to Jim with no real hope that it will reach him. Jonnie has a great deal of pride and has a strong work ethic. He is more than willing to work all day, every day, to accomplish his goals. He wants to instill this ethic in Daniel and doesn't understand why Jim feels no sense of pride when they complete the cabin. Jonnie is hard working but sometimes allows this to take over his life so that he has no time to enjoy anything.