Why does March invest in Mr. Brown’s Adirondack project?

Marmee is fascinated with Brown's Adirondack Project, which will send freed slaves to a massive plantation where they will learn how to become farmers. The more time Marmee spends with Brown, the more jealous March becomes of their relationship. When March hears that Brown is having some financial trouble and may not be able to upstart his Adirondack Project, he thought that the best way he could win back - or at the very least, purchase - his wife's affection was to assist Brown.