What are the key steps to complete the "The Iniquities of History" side mission?

The Iniquities of History is a multi-part side mission in Red Dead Redemption 2 that involves helping a historian named Professor Andrew Bell III uncover artifacts and secrets of the past. This mission is available in Chapter 4 and can be initiated in Saint Denis. To start, head to the marker near the train station in Saint Denis, where you will encounter Professor Bell. He will explain his quest to find historical artifacts and ask for your assistance.\n\nIn the first part of the mission, you will accompany Professor Bell to a dig site near the Bayou Nwa. Follow the on-screen prompts to help him dig up artifacts. Use your shovel to uncover the items, which include a Native American artifact and a Civil War relic. Be prepared for a brief ambush by bandits during this segment. Defeat them using your weapons, and ensure you protect Professor Bell, as his death will fail the mission.\n\nThe second part of the mission takes place in Rhodes. Travel to the marked location and meet Professor Bell near the saloon. He will ask you to investigate a local legend about a hidden treasure. Follow the clues to a nearby graveyard, where you will need to search for a specific grave. Use Eagle Eye to highlight the correct grave, then dig up the treasure. This part is straightforward but requires careful attention to the clues provided.\n\nIn the final part of the mission, you will travel to a cave near Elysian Pool. This segment involves solving a puzzle to access a hidden chamber. Use your lantern to navigate the dark cave and follow the markings on the walls. You will need to interact with specific symbols in the correct order to unlock the chamber. Once inside, you will find a valuable artifact and complete the mission.\n\nThroughout the mission, you will encounter various challenges, such as combat encounters and environmental puzzles. To succeed, ensure you have a good supply of ammunition, health items, and a reliable horse. Use Dead Eye during combat to quickly eliminate enemies, and always keep an eye on Professor Bell''s safety. For the cave puzzle, take your time to examine the symbols and follow the sequence carefully.\n\nPractical tips for completing The Iniquities of History include saving your game before starting each segment, as this allows you to retry if something goes wrong. Additionally, bring a bow or silenced weapon for stealthy approaches during ambushes. Finally, use Eagle Eye frequently to locate clues and hidden items, as this ability is invaluable for solving puzzles and finding treasures.