Pointillism, a painting technique using dots of color, is actually very handy tool for depicting lots of precise, minute details in vastly larger maps. First there was that mega map of racial integration/segregation, and now Robert Manduca, a mapmaker and Harvard PhD student in sociology, has created a map of every job that existed in 2010 in the United States. Using 2010 census data, the jobs are divided into categories, where red dots represent manufacturing and trade, blue dots are professional services, green dots are healthcare, education, and government, and yellow dots are retail, hospitality, and other services. Some jobs, like some Federal jobs, aren't mapped because data wasn't available. Then of course there's the obvious omission of every job created after 2010, when the country was in the midst of the Great Recession, but that's the nature of the data.