Immigrant communities in Massachusetts Gateway Cities face a number of economic and social challenges that can be difficult to understand or quantify through traditional research methods. This thesis explores the use of sentiment analysis of microblogging data as an alternative method for assessing well-being of immigrant communities, with a focus on Portuguese speaking immigrants. I collected Tweets from four key cities in Massachusetts and analyzed them using two sentiment lexicons, one in Portuguese and one in English. I compared results between languages as well as correlated with a number of traditional indicators of well-being gathered from U.S. Census data. I found that the results from the English analysis were overall more positive than those from the Portuguese analysis, but most differences were not statistically significant. I also found some correlations between the demographic data and the sentiment analysis results with promising implications for further research.