Large areas of swamp lands in the central and north central parts of the state once counted non-arable have been drained and reclaimed.
Construction of canals and the drainage of swamp lands also contribute to the protection of the state.
But mixed with the oak and chestnut or higher up are considerable hickory, birch and maple; farther up the mountain sides are some hemlock and white pine; and on the swamp lands of the Coastal Plain are much cypress and some cedar, and on the Coastal Plain south of the Neuse there is much long-leaf pine from which resin is obtained.
The state and the national government co-operate in the construction and maintenance of this system, but the Federal government did not give material aid (the only exception being the grant of swamp lands in 1850) until the exceptionally disastrous flood in 1882.
The school revenues are derived from the sale and rental of public lands granted by Congress, and of the salt and swamp lands devoted by the state to such purposes, from a uniform levy of one mill on each dollar of taxable property in the state, from local levies (averaging 7.2 mills in township districts and 10.07 mills in separate districts in 1908), from certain fines and licences, and from tuition fees paid by non-resident pupils.