React JS is an open-source JavaScript library, created with perfection by Facebook, that aims to simplify the complex process of building collaborative user interfaces. Imagine a user interface built with React as a collection of components, each responsible for outputting a small, reusable piece of HTML code. Many existing web applications are built with ReactJS and companies still choose for their upcoming projects. Therefore, there will be a huge demand for ReactJS for maintaining existing apps and creating new ones. Here is the list of Top React JS Development Companies in USA.