How to Detect Browser Back Button event - Cross Browser

Question

How do you definitively detect whether or not the user has pressed the back button in the browser?

How do you enforce the use of an in-page back button inside a sin

Answer 1

I was able to use some of the answers in this thread and others to get it working in IE and Chrome/Edge. history.pushState for me wasn't supported in IE11.

if (history.pushState) {
    //Chrome and modern browsers
    history.pushState(null, document.title, location.href);
    window.addEventListener('popstate', function (event) {
        history.pushState(null, document.title, location.href);
    });
}
else {
    //IE
    history.forward();
}