The history of RAM that you’re likely most familiar with has to do with the ever-increasing amount required to run programs through the years. The history of RAM is much deeper than that, however, and goes back to the earliest days of computing.
The earliest computers to use RAM were very large affairs and the components would appear more mechanical than digital to a modern observer. According to most historians, the Williams Tube represents the first incarnation of Random Access Memory that had any real practical usage. These tubes were first put into use in the late 1940s, just after World War II, an era where many of the first breakthroughs in computing were made.
These first RAM components were very primitive, only able to store in the range of hundreds to, in some cases, up to 1,000 bits. As these components were phased out in preference for more practical and powerful RAM options, magnetic-core memory became dominant.
Magnetic-core memory was in use until the 1970s and was the standard for decades. This type of memory utilized the magnetic charge in a metal ring to store information. The metal components were all given a unique address. This meant that information requests could be sent to one specific address without having to access that memory sequentially.
One of the most significant advances in RAM technology came when integrated circuits began to be used for RAM. This began in the late 1960s, though work on RAM using magnetic core memory persisted into the 1970s.