Early 1970's Postcards (New) - Chicago Famous Buildings in Chicago, Illinois For Sale

Unused, like-new postcards. Sold as set of five for $19. Very good condition. I cannot authenticate age of the postcards, but know they cannot be newer than mid xxxx's.
The mostly-blank backside of my St. Clair Hotel postcard has an extremely thin (1/32 inch) stain line near the top edge.
Adler Planetarium and Terrazza Promenade.... Lakefront off Roosevelt Road.......3.5 X 5.5 inches
Prudential Building.....Over Illinois Central RR tracks on lakefront.....3.5 X 5.5 inches
St. Clair Hotel......Michigan Ave. and Ohio Street....4 X 6 inches
Merchandise Mart.....North bank of Chicago River at Wells Street...3.5 X 5.5 inches.....made of linen paper
South Chicago Community Hospital.....xxxx E. 93rd Street......4 1/8 X 6 inches.