The letters was just a way to let people know what age group they fell under in the census since they did not put the actual age down. Here is an example: A(to10), B(to16), C(to 26), D(to 45), E(45+) these were for the men. F(to 10), G(to16), H(to26), I(to 45), J(45+), were for the women and K was for (others), and S was for (Slaves). Jo