As we noted in our editorial in the first issue of Volume 50, we are marking the 50th anniversary of the journal in a variety of ways, including the publication of this online special collection. With this online collection, our aim is to showcase ground-breaking articles published in the journal over the last five decades. Indeed, not surprisingly, what becomes evident when we survey the last five decades of publications in the journal is the extent to which we can track the development and evolution of many issues in the field of sociolinguistics. We have categorized the following articles according to issues that we think have been significant to the trajectory of the field, but, of course, many of the articles could be categorized under more than one category.