In what decade did the Royal Navy begin using paddle steamers to follow slaving ships into river systems?

The Royal Navy began using paddle steamers to follow slaving ships into river systems prominently in the 1840s. This period marked a significant advancement in maritime technology, with paddle steamers providing the necessary speed and maneuverability to navigate through rivers where traditional sailing ships would struggle. The use of these vessels allowed the Royal Navy to more effectively intercept illegal slave ships, particularly as they sought to enforce the abolition of the slave trade. The 1840s were pivotal as efforts intensified against the transatlantic slave trade, leading to a greater focus on maritime patrol and enforcement.

This context positions the 1840s as the correct answer, reflecting a crucial era in naval operations related to anti-slavery measures. The other decades mentioned do not align as closely with the significant adoption of steam technology for such purposes, indicating a clearer historical progression in naval capabilities during that time.