Bernardo O’Higgins
In the original Age of Empires III expansion system, Bernardo O’Higgins was the leader option for the Chilean Revolution, available to the Ottomans and Spanish. Definitive Edition replaced the old leader choice with its revolutionary-nation system, so this bonus does not describe the current DE option.

Version & availability
Choosing O’Higgins sends 10 Hussars to the Home City shipment point and automatically upgrades Hussars to the Imperial Guard level. This combines an immediate cavalry shipment with a stronger Hussar line.
Revolution bonus
In The WarChiefs or The Asian Dynasties, choose him when a Hussar force fits the army plan and the bonus supports the next fight. Check the version first; this leader-specific effect was removed in Definitive Edition.
Chile Revolution effect and version scope
O'Higgins is a historical leader choice from The WarChiefs and The Asian Dynasties era of the Revolution system. Selecting the Chilean Revolution under the Ottomans or Spanish sends ten Hussars to the Home City shipment point and automatically upgrades the Hussar line to the Imperial Guard level. The instant cavalry can support a fast post-revolt push, while the upgrade improves the continuing Hussar force; the choice therefore favors an army plan that can use mounted units immediately. Definitive Edition uses nation-specific Revolution options instead of this older leader selection, so O'Higgins' Hussar bonus should not be applied to the current Chile Revolution. Use the expansion and civilization entries to check which choices are available in the version being played.