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John Platt (1817-1872) of Platt Brothers
1817 September 15th. Born at Oldham the son of Henry Platt and his wife Sarah Whitehead
1837 Became a partner in the business of Hibbert, Platt and Sons
1842 Birth of his first (of 7) sons, Henry
1846 John Platt became the senior partner in the firm after the deaths of his father in 1842, of his elder brother Joseph (1815–1845), and of Elijah Hibbert in 1846
1848 Moved to Werneth Park
1851 Living at Wenerth Park, Oldham (age 33 born Oldham), Machine Maker Firm emplying 1,070 men and 239 boys. With wife Alice (age 27 born Oldham) and children Henry (age 8), Mary (age 7), Samuel R. (age 5), Lucy J. (age 4) and Frederick (age 1). Also a governess and four servants. Note: Living in the next abode at Wenerth Park is Samuel Radcliffe, Junior and family, presumably his brother-in-law 
1854 Became the first Liberal mayor of Oldham, holding that office for three terms (1854–5, 1855–6, 1861–2)
1857 Acquired a country estate at Bryn-y-Neuadd, Llanfairfechan
1859 John Platt, Hartford Iron Works, Oldham.
1860 Founder of Manchester Cotton Co
1861 Living at Wenerth Park, Oldham (age 43 born Saddleworth), Mechanical Engineer employing 2,109 mechanics, 1,973 labourers and 1,362 boys. Alderman and magistrate. With wife Alice (age 37) and children Mary (age 17), Alice (age 7), John H. (age 5), James E. (age 4), Emily B. (age 2), Florence S. L. (age 1) and Sydney (age 2 months). Five servants. 
1862-67 Director of the London and North Western Railway
1865 MP for Oldham until his death
1871 Living at Wenerth Park, Oldham (age 43 born Saddleworth), Mechanical Engineer and Member of Parliament. With wife Alice (age 47) and chilfren Joseph Arthur (age 19), Student Cambridge; Emily Bertha (age 12); F. S. L. (age 11); Amy Gwendoline (age 9). Also governess and five servants. 
1873 Obituary 
JOHN PLATT, M.P. for Oldham, was born on 15th September 1817 at Dobcross, Saddleworth, Yorkshire, where his father, Mr. Henry Platt, was engaged in a small way of business as a maker of woollen machinery; but owing to the wonderful development of the cotton trade the business was removed to Oldham in 1821, where his father soon afterwards became associated with the late Mr. Elijah Hibbert under the firm of Hibbert and Platt. He received his education at Dunham Massey, and at a very early age commenced his career in the business.
In 1837 he was admitted a member of the firm, under the style of Hibbert Platt and Sons, and began to take an active share in the management of the concern.
In 1843, owing to the expansion of the trade through the abrogation of the laws prohibiting the exportation of machinery, the already extensive works were found to be too small, and to meet the demands of the Lancashire and Continental markets large premises and machine shops were erected at Werneth, Oldham.
In 1851 Mr. Platt took a great interest in the International Exhibition of that year, to which his firm contributed an extensive series of working machinery illustrating the process of preparing, spinning, and weaving cotton, forming an important feature in the Exhibition; their machinery became still more extensively employed, and further development of the works was rendered necessary.
In 1854 Mr. John Platt and his brother the late Mr. James Platt, M.P., in consequence of the death of the senior partners, took in other partners under the style of Platt Brothers and Co., which was retained till the incorporation of the firm as a limited company in 1867 with Mr. Platt as chairman. To the manufacture of cotton machinery was added that of woollen and worsted machinery, and large iron forges and rolling mills were erected to meet the requirements of the works, and an extensive brick-making business was also established.
A further demand was made upon Mr. Platt's energy during the American Cotton famine, which created an immediate necessity for an improved construction of cotton gins; and the development of this new branch of business was so rapid that before the close of the war the works were turning out about 250 of these machines per week; the number of hands now employed exceeds 6,000 men.
To Mr. Platt's influence as an engineer and a large employer of labour, and to his untiring energy, the commercial prosperity of Oldham is mainly due; he took the deepest interest in all that was connected with its welfare, and the extension of the railway system as well as the acquisition of an abundant water supply is in a great measure to be attributed to him. He also greatly promoted the educational advancement of the borough by founding the Schools of Science and Art in connection with the Oldham Lyceum, and by contributing largely to the support of both institutions.
His long business experience and great administrative ability brought him necessarily into prominence in connection with most of the leading commercial questions of the day; and in the House of Commons he will long be remembered as one of the best authorities in matters connected with the industries of Lancashire.
He entered Parliament in 1865 as member for Oldham, and retained his seat till his death, which took place on 18th May 1872 in the fifty-fifth year of his age, in Paris, where he was seized with an attack of typhoid fever while returning to England from a continental tour.
He became a Member of the Institution in 1859, and in 1866 contributed a paper on machinery for the preparing and spinning of cotton (see Proceedings Inst. M. E. 1866 page 199).