In addition to being a farmer, he served as bailiff (lensmann) in Gjemnes from 1836 to 1854. He was elected to the Storting for nine periods, from 1827 to 1828, from 1833 to 1841, and from 1843 to 1854. He is particularly known for his agitation for farmers" interests.
His publication from 1830, popularly called Ola-boka, was instrumental in doubling the number of farmers (from 21 to 45) elected at 1833 Parliamentary election.
He is regarded as Father of Formannskapslovene from 1837, based on his draft from 1833. A monument to Neergaard stands next to County Road 341 near his birthplace.