That is not true. Agriculture suffered busts due to the cyclic calamities, droughts, etc of mother nature.

The currently fashionable attitude toward the business cycle stems, actually, from Karl Marx. Marx saw that, before the Industrial Revolution in approximately the late 18th century, there were no regularly recurring booms and depressions. There would be a sudden economic crisis whenever some king made war or confiscated the property of his subject; but there was no sign of the peculiarly modern phenomena of general and fairly regular swings in business fortunes, of expansions and contractions. Since these cycles also appeared on the scene at about the same time as modern industry, Marx concluded that business cycles were an inherent feature of the capitalist market economy. All the various current schools of economic thought, regardless of their other differences and the different causes that they attribute to the cycle, agree on this vital point: that these business cycles originate somewhere deep within the free-market economy.