The Generation of Dispersion (Dor Ha-Haflagah) is the traditional term to refer to the people who built (or attempted to build) the Tower of Babel (Bereshis 11). The Torah states that the “entire land was safah ehas u-devarim ahadim” which seems to imply that everyone in the world spoke one language and that, as a consequence of the failed attempt, God decreed that people henceforth speak many languages. A possible historical problem with this story is that we seem to be able to document the existence of other languages at that time (recall that Avraham lived shortly afterward). The following alternate explanations of the episode were offered before any such historical evidence was known, and is therefore free from the charge of apologetics.
The first thing to notice is that in the previous chapter, there are already references to multiple languages. Regarding both the descendants of Ham and Shem, the Torah says that each family had its own language (Bereshis 10:21,31).
R. Ya’akov Tzvi Mecklenburg (Ha-Kesav Ve-Ha-Kabbalah, Bereshis 11:1) quotes a Ralash (anyone know who this is?) who suggests that the entire story is only about the people in the region of Yoktan, which was discussed immediately prior to this episode. See his commentary for how he, typically, expresses great care for the precise wording of the passage. This, of course, alleviates the entire problem because the single language was only in one region. Other regions had different languages, as implied in the previous chapter.
The Talmud Yerushalmi (Megillah 1:9) records two opinions regarding the above generation. One is that the people spoke seventy languages and the other is that they spoke the Holy Language (i.e. Hebrew). However, the first view is extremely difficult to understand. The verse specifically states that they spoke one language – “safah ehas” – so how could this talmudic sage say that they spoke many languages? The standard commentaries on the side of the Yerushalmi, Korban Ha-Edah and P’nei Moshe, explain that the people spoke different languages but everyone understood each other’s languages so it was as if they all spoke one language. This, too, would solve the above problem.
R. Barukh Ha-Levi Epstein, in his Torah Temimah (Bereshis 11:1), offers another explanation to this view in the Yerushalmi that anticipated the views of many contemporary academic biblical scholars. R. Epstein suggests that the people of that time each spoke their own tribal language but, additionally, spoke a universal language that was common to all. Everyone spoke Hebrew, but everyone also spoke their own local language. This is very similar to the way English and Spanish are treated today in many parts of the world.