When I played AD&D 1e and 2e Orcs were listed as lawful evil in the Monster Manual. Lawful Evil as their alignment was consistent with other similar races like Goblins, Hobgoblins, and Bugbears. To my surprise the D&D 5e Monster Manual lists Orcs alignment as chaotic evil, with a description of how Orc tribes work. Why was the Orc alignment changed?
Plenty of AD&D 1e and 2e adventures had Orcs as mercenaries which fit the LE willingness to follow orders. Orcs as CE seem unsuited to organization beyond a tribe as they follow only the strong. The AD&D 2e Monster Manual even suggested that trade was possible with Orcs if you had a well defended enough settlement that trade would be easier than conquest.