Little House on the Prairie (1974)

Season 6: Episode 3

Each student must trace their family tree for a school assignment. Albert is unsure how he can do the assignment. The Ingalls decide to legally adopt Albert, but run into problems when Mr. Quinn, Albert's father shows up. He wants Albert until he sees him. Albert pretends to be blind with the hope that his father wouldn't want him. The blindness does the trick. Albert is legally adopted by the Ingalls.