Civil war and persecution have led to mass movements of people across national borders. You will be able to find a wealth of journalism on this subject in relation to Darfur/Sudan and Syria.
The more recent story to emerge is the story from Syria. The country is engaged in a civil war and many citizens have been forced to flee. Neighboring countries have reportedly absorbed over 25% of the entire Syrian population.
The connection between these stories and Steinbeck's novel is that of forced migration. Many other stories of human sacrifice can be found in the news from around the world - including the United States.