"More commonplace" is a tricky question. Pascal had noticed that , because pressure equalized in a hydraulic system, a small pump could create a large force from a large piston. James Rumsey had realized water could be used as a way of transmitting power, and the hydraulic cylinders and motors in his 1791 British patent are quite modern- but he never built any of them, and he was noticeably vague about seals- a very critical thing. After Joseph Bramah invented the cup seal and the hydraulic press in 1795, and William George Armstrong came up with hydraulic motors and cranes, circa 1845, it's possible to say that hydraulic power was being commonly used. But the key to what you see now, with it employed in earth moving equipment , industry, etc. on a very wide scale, is the invention of the o-ring seal by Christensen in the US in 1937 . The cup seals of Bramah and Armstrong's time ( and still found in things like lever-operated well-pumps) wore out fairly quickly- were simply rubbed away by constant use until they began to leak, and they needed regular replacement. O-rings are much longer lasting and seal much better, one of those inventions that are very inconspicuous but quite sophisticated and very important. What is maybe also tricky about your question is that ( as the article says) the US government appropriated the patent for O-rings during WWII and let all the war industries make and use them. I am not sure if this caused a boom in the development of hydraulic systems, or if they were already booming and would have grown anyway. Certainly the development of tougher synthetic rubbers during and after the war also helped.