Definition of "at ease"

At this command, the soldiers will carry their firelocks as they please, as prescribed in the soldier's drill, No 120, and are no longer required to march with the same step, or to observe silence ; the files will march at ease ; but they will be careful not to confuse the ranks, and the front rank must never pass before the guide, who is on the directing side, and that the two last ranks always preserve about three feet distance from each other.

1809, William Duane, The American military library

If the column be composed of a considerable number of battalions, the commander can march it at ease, as a column of route.

1821, Pierce Darrow, Winfield Scott, Scott's Militia Tactics, page 133

When marching at ease, you must march in orderly ranks in silence, but you need not keep step or march at attention.

1984, Wayne R. Gustafson, Military requirements for petty officer third class, page 3-28