c1910 Picture Postcard - Deaf Mute School In Sioux Falls, South Dakota ~ #-10380. Vintage Picture Postcard is selling as a used standard size postcard. Non-Posted Vintage Picture Postcard shows light wear, see pictures. Postcard was published by: S.H. Knox Co. - AKA - Acmegraph Co. in the USA. Very Nice Non-Posted Vintage Picture Postcard of the Deaf Mute School in Sioux Falls, South Dakota. See pictures for condition information and card details.