Received his professional education in Edinburgh, Dublin, and at University College Hospital, London. He began practice at Wigan in 1831, and removed to Bolton in 1837. He soon gained a lucrative practice, but in 1843 suffered from rheumatic fever followed by heart disease and bronchitis, so that in May, 1863, he was forced to retire from practice to Stockport. During his active life he was for five years Surgeon to the Bolton Infirmary, and for fifteen years maintained an institution for the gratuitous treatment of diseases of the eye and ear. For three years he was a member of the Bolton Town Council, also he was a JP. The occasion of his retirement was marked by a presentation of silver plate by the gentry to him and Mrs Chadwick. On the same occasion seven thousand of the working classes subscribed for a full-length portrait of him and gave a cabinet writing desk to Mrs Chadwick. Subsequent to this, in 1868 and 1869, Chadwick and his wife made over to trustees £22,000 to build and maintain an Orphanage for Children of the Bolton Union. A bronze statue of Chadwick was erected by subscription in Bolton Town Hall Square, and unveiled on August 1st, 1873. He had married in 1831. Chadwick died at Peel House, Southport, on May 3rd, 1876, and by his will left £5000 as an endowment of a Children's Hospital if erected within four years; and also £5000 towards the erection and maintenance of a Natural History Museum in Bolton Park. The remainder of his personal property passed to the Trustees of the Orphanage, and thus enabled the original design to be completed. He was buried in a vault in the Parish Church, where his two children, a son and daughter, had long lain buried, the parents in their memories had contributed to many charities.