Joined Asa Packer in the contracting business in Mauch Chunk in 1833..

His youth until eighteen was spent upon the homestead farm amid the varied employments of a farmer's son, alternating with periods at the neighboring country school. About 1833 he removed to a Mauch Chunk with his brother-in-law, Asa Packer, and devoted the first two years to the occupation of a boatman on the Lehigh Canal. The four years following were spent as clerk in a country store, after which (in 1839) he engaged in the mining and shipping of coal in Schuylkill County. In 1844 he returned to Mauch Chunk and from that (late until the beginning of the construction of the Lehigh Valley Railroad in 1851 was engaged in the preparation and shipping of coal from the Nesquehoning mines, worked by Messrs. Mapes, Packer & Harlan, under contract with the Lehigh Coal and Navigation Company. He also superintended the building of what is known as the "Stone Row," and "Packer's Corner," a building occupied by judge Packer previous to the erection of the mansion where he subsequently resided, and where his death occurred.

Mr. Blakslee assisted in the construction of the Lehigh Valley Railroad, and was conductor of the first coal train that ran over the road, subsequently acting as conductor for eight years on a passenger train on the same road. In the spring of 1863 he was appointed superintendent of the Mahanoy Division of the Lehigh Valley Railroad, and in 1871 was elected president of the Montrose Railroad, extending from Tunkhannock, Wyoming county, to Montrose, Susquehanna county, the construction of which he personally superintended. In 1878 he was elected a director of the Lehigh Valley Railroad, and for a number of years was a member of the executive committee of its board of directors. During the greater part of his life he was identified with important business enterprises, but these, however, did not absorb his attention so completely as to make him indifferent to the prosperity of the community in which he resided. As a trustee of Lehigh University he exerted a powerful influence in favor of education. In 1851 he was elected to the responsible position of treasurer of Carbon county, the duties of which he performed with credit to himself and with satisfaction to his fellow citizens. He was a trustee of the estate of the late Asa Packer, having been appointed to the vacancy occasioned by the death of H. E. Packer. He was a member of St. Mark's Protestant Episcopal Church, was appointed a vestryman in 1846, and was also a member of the standing committee of the diocese. He was a Democrat in politics.