In From Flintlock to Rifle, Professor Ross traces the development of infantry tactics from the mid-eighteenth century, when infantry fought in rigid linear formations, until the second half of the nineteenth century, by which time infantrymen with rifled weapons were learning to advance in open order and use aimed fire. The author demonstrates that this transition in tactics involved social and technological change as well as military innovation.

Old Regime armies, recruited from a narrow social base and armed with slow-firing, short-range, inaccurate weapons, relied upon harsh discipline and formalized evolutions to attain tactical proficiency. When the French Royal Army collapsed it was replaced with a mass citizen army. This contained elements of the old tactical system but placed a new emphasis on mobility, flexibility, and individual initiative.

Napoleon's rivals either imitated aspects of the French system or sought to copy the spirit of the new tactics, engineering social reforms from above and creating their own citizen armies.

After 1815, generals and politicians continued to develop tactical doctrines that embodied the lessons of the Napoleonic wars. Industrialization had a swift impact on weapons technology and firearms improved in range, accuracy, and rate of fire. As a result, military men had to modify their drill and battle tactics to cope with increased firepower. A process initiated by the French Revolution was thus accelerated by the Industrial Revolution.