In the US, lockstep marching or simply lockstep is marching in a very close single file in such a way that the leg of each person in the file moves in the same way and at the same time as the corresponding leg of the person immediately in front of him, so that their legs stay very close all the time.
Lockstep marching was a characteristic trait of American prisons of the 19th century. "Inmates formed in single file, right hand on the shoulder of the man in front, left hand on the side; the convicts then stepped off in unison, raising the right foot high and shuffling with the left." The reason for the shuffling step was the chain that connected the legs of a chain gang.
In the Auburn Prison, John Cray developed the following form of the lockstep, as part of the penal system that has become known as the Auburn system, developed in the 1820s: "The lockstep was a method of walking where each man walked with his arms locked under the man's arms in front of him". This system was devised to keep prisoners under control during mass marches of several hundred prisoners from work places to mess, to cells, several times a day. Also, the inmates in lockstep were often required to alternate which side they were looking toward, to preclude communication.
The term acquired a number of other meanings by the way of analogy, referring to synchronous or imitating movement or other behavior, following something or someone ("in lockstep with..."), often with a pejorative tone.
- Maltby, Isaac (1811). The Elements of War. Thomas B. Wait. pp. 18–19. Retrieved 2011-03-18.
- "The Oxford History of the Prison: The Practice of Punishment in Western Society", Oxford University Press, USA; Hardcover (November 1995) ISBN 0-19-506153-5; Reprint edition (October 27, 1997) ISBN 0-19-511814-6
- Harvey R. Hougen, "The Impact of Politics and Prison Industry on the General Management of the Kansas State Penitentiary, 1883-1909, Kansas Historical Quarterlies, 1977 (Vol. 43, No. 3), pages 297 to 318
- "Both Sides of the Wall: Auburn and Its Prison", The Citizen, April 10, 2003 on Pages D8, D9, and D15
- "History of Parole in Canada"
- Ohio Penal System
- [Life and Death in the Third Reich, p. 99, Peter Fritsche]
- It was abolished gradually, by separate acts in different places:
- Sing Sing: The prison lockstep was abolished in 1900 by the order of the Superintendent of State Prisons Cornelius Collins — '"Sent up the river" - A History of the Sing Sing Correction Facility', DOCS Today, March 1998
- New Jersey: "During Mr. Osborne's tenure as warden of the New Jersey prison he abolished the lockstep,..." 
- Illinois: (1898-1903) "Changes to prisoner treatment also occurred during this period. The congregate movement of prisoners, the lockstep, was abolished,.." 
- Nevada: Raymond T. Baker: "He abolished the lockstep"