 Data graphics use basic design elements to show what the eye can't see. Dots on a map help us see geographic patterns. In 1855, Dr. John Snow tracked cholera on maps of London. He discovered clusters of cases around a water pump. These maps proved that water carries cholera. This interactive map by ProPublica explores Cancer Alley, an area near New Orleans. The region is dotted with hundreds of chemical plants and oil refineries. Residents in this predominantly black area suffer from many chronic diseases. New plants are still being built here despite the known risks. Levels of toxic particles are shown in shades of pink. These high levels of pollution are associated with higher death rates from COVID-19. This global map is published by Johns Hopkins University, JHU. Here, red dots show COVID-19 cases. As we zoom in, the data becomes more local. Soon, precise numbers appear with each dot. This interactive story uses dots to illustrate how the virus got out. Many of the first known cases clustered around a seafood market in Wuhan, China in 2019. Four cases grew to dozens by the end of December. The true size of the outbreak was much larger. At least 175,000 people left Wuhan on January 1st. The departures accelerated over the next three weeks. Thousands of travelers were infected. By the time Chinese officials restricted travel from Wuhan, local outbreaks were already growing. As the disease moved across China in early January, international travel continued as normal. Thousands of people flew to cities around the world. Cases turned up in Tokyo, Singapore, Seoul, Hong Kong and Seattle. In the US, President Trump said the virus will not have a chance here. But by then, the virus had a secure foothold that continued to spread across the country. A line graph connects a series of dots. There are many ways to draw the line or to smooth it out into a curve. This line graph shows the shape of a cholera epidemic in 1849. The jagged blue line rises exponentially as the bacteria infect more hosts. The blue line falls as immunity halts the spread. The CDC introduced the concept of flattening the curve way back in 2007. The tall purple mountain shows an uncontrolled epidemic, no social distancing and no masks. A low wide hill stretches out in front of the mountain, showing the potential benefits of intervention. Ultimately, the CDC graphic told a story about what might happen in the future. The purple mountain is a story based on the shape of past epidemics. A new version of flatten the curve appeared early in the COVID-19 pandemic. The slogan, flatten the curve, went, as they say, viral. Here's what the curve really looks like. The pandemic doesn't have a single peak. The red line rises and falls several times. The curve was flattening by early summer, but then a new curve emerged, heading towards the catastrophic peak of winter 2021. The curve came down, only to rise again in the summer. This map shows how the virus spiked in waves across the US. Red triangles become sharp spikes. Each one is a line graph. The rising and falling spikes show that a global pandemic is made of local outbreaks. Traffic signs use color to command action. Stop, caution, go. Alyssa Eckert and Dan Higgins created this 3D medical illustration at the CDC in January 2020. A virus has no color, so why are the spikes red? The illustration was designed to warn people. Note how the JHU dashboard uses color. Red signals the number of cases. Yellow signals the incidence of cases in a population. Green represents vaccinations. White represents death in many cultures. White is spiritual, marking loss with points of light. This New York Times map uses yellow and red to track COVID-19 hotspots in the US. Just a month later, the cases were much higher. Purple was added to the scale. Shades of yellow, red, and purple show the pandemic moving in waves across the map. These maps of Chicago steer clear of emotionally loaded colors to avoid stigmatizing any group. Neighborhoods in green are predominantly black. These neighborhoods also have a lower life expectancy, shown in white. Dark purple shows high rates of hypertension. Such illnesses are associated with higher mortality from COVID-19. All these dots, lines, and colors represent human lives and human suffering. The following interactive graphic was published on the occasion of 100,000 COVID-19 deaths in the US.