His attempts to control the slave trade generally failed, and when he died of smallpox in 1789, his son Agonglo came to the throne and ended many of his policies.

The slave trade was the major economic resource for the kingdom and the king's personal finances, but Oyo and other inland traders had begun raising rates and playing port cities against one another.

[1] Kpengla had the opportunity to either improve the kingdom's position as middleman or to start slave raiding which would cause anger by Oyo and others.

Having fulfilled his part of the agreement, Kpengla grew angry when Oyo and Porto-Novo continued to trade actively as a rival port to Whydah.

The next year, he created a royal monopoly over trade at Whydah, controlling all English and French imports (except for Brazilian tobacco).

This width of this road and its maintenance were unique in West Africa for the time and the Cana to Abomey stretch was maintained and impressed European visitors for the next century.

According to Abson, in 1779 the king; ordered all his subjects to set about clearing the paths, giving each caboceer (chief) a string, measuring ten yards, the intended width of roads.

With incredible labour and fatigue, a passage was cut through the wood at Apoy; the gullies were filled up, and the hurdle bridges, over the swamps, were widened.