late 19th century american ornamental cast bronze "thistle" pattern passage door residential backplate and matching doorknob. the intricate organic design is attributed to chicago architect louis sullivan. the escutcheon features deeply lobed leafage surrounded by delicate scrolls. the intricate design motifs bear strong resemblance to several designs used throughout louis sullivan's auditorium building (see additional pictures of newel post and staircase baluster panel). the backplate and doorknob were fabricated by the chicago hardware company, chicago, il. exhibits an attractive surface patina. the doorknob contains a chicago-niles patent shank. original cast brass swinging keyhole cover intact. measures 17 x 3 1/2 inches.