John Oliver York was born in Birmingham, England on March 9 1811, a son of John York, a banker. On January 23, 1812, he was baptized in Stony Stratford Buckinghamshire, the family residence. He was probably sent away to school but where is unknown. He then entered the office of a civil engineer for a course of studies, during which time he lived in London.  On September 24 1831, he married Helen Kinnaird in Westminster, London. Helen was the daughter of Hugh Kinnaird, at that time in Royal Service to William IV.

  In 1832, John Oliver took up the position of principal engineer (Ironmaster) at the Horseley Iron Works in Tipton Staffordshire. Five children were born while the family was in Tipton:  Ellen Ann in 1834 (she only lived for 10 days);  Frances Elizabeth in1835;  Ann in 1837; Oliver in 1838 and Henry Kinnaird in 1840. Sometime in 1840, John Oliver left the Horsely Works and returned to London. During his eight years as Ironmaster at Horseley, he gained the knowledge, experience and business contacts that allowed him to have a very successful subsequent career in construction and railway building   In June of 1840, he was admitted into the Institution of Civil Engineers, sponsored by Henry Fowler, likely the engineer he had studied under. In May of 1841, a son John was born. He died very young but when is unknown. In the same year, John Oliver had serious financial difficulties and went into bankruptcy. However, a positive event in that same year was that he was granted a patent for "improvements in Railway Axles and Wheels" (the first of five patents that John Oliver was granted). While at Horseley, the iron works had constructed several railway engines. In those early days of the railway, engines were in a constant state of improvement. Problems begat innovation, experimentation and ultimately, improvements. John Oliver's first patent was one such improvement.

  During his time in Horseley, John Oliver would likely have had contact with Thomas Brassey, the most successful railway builder of his time. By 1843, Brassey had begun operations in Europe. He hired John Oliver to manage one of his  foundries near Evreux, France (about 60 miles west of Paris) and the family  moved to France. Helen Maria was born in 1846 but the only record of her birth was her baptism in England in 1847. So whether she was born in France or England is unknown but the family was most likely living in France from the time they went there in 1843.  John Oliver built and managed another foundry for Brassey in northwestern France and in 1853, began his own business as a construction agent. He took the contract (probably as an agent for Brassey) to build a railway in eastern France. In the same year he also took the contract to provide gas lighting for the town of Seville in Spain. His son Oliver worked with him as a draughtsman on this project, presumably in an engineer-in-training capacity, having entered the office of his father.

  John Oliver's next project was probably his most significant construction challenge. Napolean III decided to make his statement to the world by having an International exhibition that would surpass the scope and success of the one in England in 1851. The main building, the Palais de l'Industrie, was designed and engineered by two Frenchmen, but John Oliver received the contract for the actual construction. He was made a Chevalier of the Legion of Honour for his accomplishment.