This effect, in which the colors of cards in two packets appear to change to match the colors of a “leader” cards placed in front of them, is generally credited to Dr. Reinhard Rohnstein of Berlin. This attribution was established incompletely by Faucett Ross, who reported having, in 1929, found a letter from Ottokar Fischer in which the effect was described. Ross later mentioned the trick to Dai Vernon, who added “many touches and improvements”. Vernon's routine, with Ross's title of “Follow the Leader”, was eventually published in Vernon's Five Close-up Problems, 1933, authored by Ross. There Ross stated that “the root of the idea […] was not original with Mr. Vernon”, but Ross did not name the originator. He published more complete information in Ibidem, No. 6, Jul. 1956, (p. 107 of the book compilation, Ibidem, Volume 1, 1993). Ross repeated this information when Five Close-up Problems was reprinted in Early Vernon, 1962, p. 43. However, in both histories, Dr. Rohnstein was still not named, but identified only as “a Vienna amateur”. His identity came out only years later; see Connie Bush's Color Isolation by Joseph K. Schmidt, 1988, p. 32. However, the source on which this identification rests is not stated.
Graham Adams made a connection between Follow the Leader and a trick by Martin Chapender, which consisted of a single transposition of a packet of court cards with a packet of spot cards; see Wilfred Hutchinson's Conjurers Chronicle, Vol. 16 No. 1, May-Jun. 1934, p. 945. Peter Warlock, in his Creation of a Magical Effect notes, produced for his Apr. 24, 1951, lecture, made the same connection (p. 11); see also his article in New Pentagram, Vol. 13, No. 10, Dec. 1981, p. 76. If valid, Chapender having died in 1905, it is likely he would have preceded Rohnstein in conceiving the effect. However, two salient characteristics of Follow the Leader are that “leader” cards are exchanged as the presentational trigger for the transposition, and multiple transpositions occur. Chapender's effect features just one transposition, and while Warlock states in the notes cited above that Chapender used leader cards, he concedes that this is speculation and omits this point in his Pentagram article; and two earlier descriptions of the Chapender trick make no mention of this presentational ploy: See The Sphinx, Vol. 5 No. 2, Apr. 1906, p. 20, for a description of Chapender's effect; and for the method see “Twelve Court Cards in Glass Change Places with Twelve Ordinary Cards Held in the Hand” in Practical Conjuring by James Wakefield (writing as James Carl), 1911, n.p.
Reinhard Müller has pointed out a more suitable early Follow the Leader effect: “Geheimnisvolle Wanderung” in Offenbarungen aus dem Reiche der Kartenkunst by Leopold Figner, 1924, p. 60. Figner offers a method using a Pass and a second method using gaffed cards, to achieve a single transposition of a packet of red cards and a packet of black cards. Unlike the Chapender effect, Figner's does feature the open trading of leader cards to cause the packets to magically transpose.
See also: Daley's Delight.