Published by Street & Smith. Dates range from October 5, 1915 to March 5, 1917. This pulp is considered to be the first all mystery-detective magazine and the first issue features a Nick Carter story. Each issue is approx. 6.75x10" with an average page count of 128. Group includes a complete run from vol.1 #1 Oct. 5, 1915 through vol.5 #2 Oct. 20, 1916 and first five issues from 1917. Two issues were published per month. Numbers and dates include: vol.1 #1-6 Oct. 5, 1915-Dec. 20, 1915; vol.2 #1-6 Jan. 5, 1916-March 20, 1916; vol.3 #1-6 April 5, 1916-June 20, 1916; vol.4 #1-6 July 5, 1916-Sept. 20, 1916; vol.5 #1 & #2 Oct. 5, and Oct. 20, 1916; vol.6 #1-5 Jan. 5, 1917-March 5, 1917. Vol.1 #1 has small top cover tear and bit of spine tip wear. Fine. Most issues average Fine/VF condition with a few minor cover tears here and there and a few edge creases. Exceptions are vol.1 #4 which has no back cover and is missing last page and is just Fair but contains complete first Red Raven story; vol.2 #5 March 5, 1916 with the first of 320 stories by McCulley (J.M. Stone) which also includes first appearance of Black Star has heavy cover wear with covers just Fair but inside Good; vol.4 #4 for Aug. 20, 1916 has heavy cover wear and insect damage and is Poor; vol.5 #5 for Oct. 5, 1916 has a 2.5" piece off cover with insect damage at extreme page edges overall Fair/Good. Vol.6 #5 for March 5, 1917 has insect damage at extreme right edge with 2" piece off spine top and is just VG. Issues overall clean and tight with non-brittle creamy pages. An impressive instant collection of this famous early pulp.