In November, 1851, Mr. Pillsbury was appointed purchasing agent of the Concord Railroad, and commenced his duties in the following December, having in the meantime moved his family to Concord. For nearly twenty-four years he occupied this position, and discharged its duties with rare business ability, showing wise judgment in all his purchases, which amounted to more than three million dollars, and settling more cases of claims against the corporation for alleged injuries to persons and property than all the other officers of the road. He had great quickness of perception and promptness in action, two wonderful business qualities, which, when rightly used, always bring success. During his residence of twenty-seven years in Concord, he gradually acquired a position which all may envy. Various positions of trust, both in public matters and as a private adviser, were discharged by him most faithfully. He was one of the committee appointed by the Union school-district to build the high school and several other school buildings. He was also interested in the erection of several of the handsome business blocks and fine residences in the city. In the year 1864, Mr. Pillsbury, with others, established the First National Bank of Concord. From the first he was one of the directors, and in 1866 became its president, which position he held until his departure from the state. He was also more instrumental than any other person in organizing the National Savings Bank in 1867. Of the savings bank he was the first president, and held the position until 1874, when he resigned. During Mr. Pillsbury's management of the First National Bank, it became, in proportion to its capital stock, the strongest bank in the state. Up to December, 1873, when the treasurer was discovered to be a defaulter to a large amount, the savings bank was one of the most successful in the state; but this defalcation, with the general crash in business, required its closing up. Its total deposits up to the time mentioned exceeded three million dollars. The bank finally paid its depositors nearly dollar for dollar and interest, notwithstanding the large defalcation by its treasurer.