Intra American and Trans atlantic trade of enslaved africans



This data visualization incorporates both the Trans-Atlantic Enslaved African Trade and the Intra-American Enslaved African Trade in which an estimated 12 million Africans were kidnapped from their homeland and sold into slavery. This dataset was taken from The organization states, “The New Voyages website itself is the product of three years of development by a multi-disciplinary team of historians, librarians, curriculum specialists, cartographers, computer programmers, and web designers, in consultation with scholars of the slave trade from universities in Europe, Africa, South America, and North America.” This visualization shows not only how many countries took part in this barbaric institution but it also allows viewers to see the rate over a 400 year time span that the institution of slavery took place.

In order for me to gain a better understanding of this data I needed to transform numbers like (400 years & 12 million) into actual information one could digest. The Trans-Atlantic Slave Trade is impossible to sum up in bar graphs, histograms and pie charts but by utilizing these tools I was able to uncover some interesting findings. Some of the questions I was interested in were the years that saw the highest trade of enslaved Africans? What leaders participated especially after the ban of 1807? Where is the accountability? What’s the story behind 1859 in New Bedford, Mass where we see 1,680 enslaved Africans being transported to S. America which was on the cusp of the abolition of slavery?


The New Voyage website has been on my radar for awhile so I utilized their dataset to create my data visualizations as it was the most thorough investigations of the Trans Atlantic Slave Trade I’ve come across. This dataset included eight columns and over 36,000 rows of Voyage origins, landings, purchases, year of arrival, totals of enslaved Africans, names of captains and their boats. My first instinct was to create a map visualization that showed the global impact of this injustice but since the dataset did not include latitude and longitude I decided to take a different route. I could have manipulated the file but I realized there was already a very detailed representation of this on the The New Voyage website so I pivoted my research and process. I was interested in dates, origins and the amount of Africans affected by this inhumane exploitation. I worked with a few different sites but none of them were as intuitive as Tableau for my dataset. After importing my csv file to Tableau I quickly wanted to start animating my data which gave me more insight into what I was trying to accomplish which was the translation. There is a lot of complexity and messiness I believe we try hard to oversimplify when creating our visualizations which sometimes comprises the message we’re trying to convey by minimizing its value. It’s important to see and acknowledge the history or impressions that the data leaves behind as it moves through space and time, else it runs the risk of being forgotten or in this case erased. The animation tool gives people who utilize this graph the opportunity to control the level of visuals they receive also the filter allows you the opportunity to create the value range you’d like to focus on. I utilized the filter to drill down into specific areas that I found interesting/disturbing like the New Bedford  data (figure. 1).

figure. 1

I was also able to create a bar graph that gave me different perspectives, one of which showed the whole picture and the other filtered a specific date for my question about what year saw the highest trade of enslaved Africans? (figure 2. – figure 4)

(figure 2-4)

Although some of these images look like 8bit graphics I appreciate them not overshadowing the information within. This is also another animated image with a filter that allows the viewer a lot of control over what they want and don’t want to see. In this particular graph the color represents the location where the voyage began. The x axis is the time or year of disembarkation and the y axis holds the number of enslaved Africans on each voyage.


Brazil had the highest importation of enslaved Africans more than any other country, an estimated 4 million which is represented in the pink and yellow. It was also one of the last places along with Cuba to abolish slavery which brings a bit more clarity around why whaling boats from New Bedford Massachusetts were traveling to Cuba and Brazil. There was clearly a steady increase from mid 1500s to 1829 with a very slow drop off only to come to completion with the 13th Amendment. Below the dashboard gives the user more flexibility to explore the dataset with customizable filters on the right hand column.



Below in (Figure. 1) we see over 467,327 null or n/a variables that represent the place of origin where voyages started. A deeper look at this number showed there is incomplete information but it’s not necessarily null meaning there are still pieces of information that can be employed. There are a number of reasons for this but the main ones this report explores are erasure and integrity. This seems very intentional especially towards the end of the timeline we see a major uptick in the unknown variable. Deliberately not keeping a complete record is a great way to hide evidence and to evade responsibility. If the law already doesn’t apply to you this makes your seat in history more polished. The second being the responsibility of the person left to interpret this massive undertaking. A lot of names of certain places may have changed or not been known so cleaning the data with integrity is important. The decision of choosing null rather than the wrong coordinates might have been one of the only options available in keeping the data honest.

figure. 5

Brazil and Cuba

This section shows the results after filtering Brazil (Figure.6) and Cuba (Figure.7) out of the overall data.

figure. 6
figure .7

Visually we can see how much real estate both of these countries are taking up on our bar graph but looking at the numbers combined there were approximately 456,373 enslaved Africans being imported almost completely after 1808 as (Figure. 8) shows below.

figure .8

Brazil and Cuba were two of the last places to abolish slavery, Brazil ending slavery in 1888 and Cuba in 1886. We will take a look at why and how this was happening further in our investigation as we find some outliers that build a more complete story.

The Act of 1807 Prohibiting the Importation of Enslaved Africans

Did the act of 1807 decrease the amount of enslaved Africans being imported? The answer is no. From 1514 to 1807 approximately 2 million enslaved Africans were being exploited and after 1807 we see in just 50 years over 900,000 enslaved Africans being imported. Another way to look at this is that it took nearly 200 years from 1514 to 1754 to reach 900,000 compared to 50 years after The Act of 1807. It would seem between technology and legislation there is indeed some correlation to the rate and degree in which Black people have been and continue to be oppressed.

UX Research

There were a handful of people who interacted with these visualizations that all had similar first impressions. I chose to show them the visualization without any background or subject headers. Their initial thoughts on Figure 1 was that it was really beautiful. I then provided context and they were in awe of how something so terrible could be presented so visually pleasing. After introducing the context everything seemed a bit overwhelming for users but they didn’t shy away they just took a moment to gather themselves before proceeding. All of the users knew very little about the Trans-Atlantic and Intra-American Trade of Enslaved Africans so it was interesting to see them react to the numbers and events. Overall, the feedback I received about this project was that it was great but people needed time on their own to digest all the information being presented.


Figure.9 from the The New Voyages site is on of the most moving visualizations I’ve seen in awhile. It’s a time lapse depicting the Trans Atlantic and Intra American Trade of Enslaved Africans. It’s explicit, detailed and the color selection is recognizable as they chose colors most often used on maps. I also appreciate the map from The True Size website which is represented in Figure 10. It’s interactivity is incredibly informative and accessible without being too academic. You’re able to move different countries, states and regions around the map to gain some perspective on how scale works.

figure .10


  • Tableau Desktop
  • The New Slave Voyage website
  • Numbers


There is a lot of information here but I didn’t want to dilute the data in an effort to preserve the integrity of the visualization. I also made the choice to show the history through animation which created a watercolor blur aesthetic (figure.9). I’d like to develop this more by telling a detailed story about what was happening globally but especially in Africa during this time as the history is so rich. It would also be nice to align dates on the graph with other historical timelines like laws and other major events in the U.S. I attempted to create a map which you can see is the header image but there are so many null values that it was difficult to clean this data. I tried entering these coordinates in manually but there are so many obscure regions and countries that don’t exist anymore that it’s was very difficult to find locations I felt 100% comfortable with including. In the future I’d like to work with some historians who specialize in the Black (Africana) History so that I can give a better representation of the data from specific regions. Lastly, there were so many variables it was a bit difficult to be explicit about my color palette, I’d like to develop this more by possibly putting this on an off white backdrop and customizing the colors.

Figure. 5