Data visualization with a poetic take on the data — historical immigration to the U.S. is shown as a set of tree rings (1830-2015).
As time advances, the tree grows, forming rings of immigration. Each ring corresponds to a decade. Cells are deposited in layers, and each cell corresponds to 100 immigrants that arrived in that decade from a specific region outside the U.S.
Trees in their natural setting have annual growth rings that reflect varying environmental conditions; the rings’ forms are neither perfect circles nor ellipses. The algorithm is inspired by this variation and accordingly deposits immigrant cells in specific directions depending on the geographic origin of the immigrant. Rings that are more skewed toward the country’s East, for example, show more immigration from Europe, while rings skewed South show more immigration from Latin America. With this, it is possible to observe the quantity of immigration through the thickness of the rings. The color of the cells corresponds to specific cultural-geographical regions.
Micro-data were collected, consisting of millions of samples of questionnaires from the U.S. Census. This data registers the U.S. state of residence, age, and country of origin of each person since 1790. Using this data, we calculated estimates for the number of immigrants who arrived in each decade. The system was implemented in Processing and uses a physics engine to deposit cells and make them interact with each other.
The tree metaphor: Trees can be hundreds, even thousands years old. The cells grow slowly, and their pattern of growth influences the shape of the tree’s trunk. They are the result of a slow process that occurred a long time ago. This idea lends itself to the representation of history itself, as it shows a sequence of events that have left a mark and shaped the present. If cells leave a mark in the tree, so can incoming immigrants be seen as natural contributors to the growth of a trunk that is the U.S. It carries the idea that these marks in the past are immutable and that cannot be erased regardless how you read them. Additionally, it embodies the concept that all cells contributed to the organism’s growth and that they are all part of it. The cells and rings in a tree are nature’s own way of organizing information, which can serve a reference to how we can spatially organize immigration data for presentation.
Steven Ruggles, Katie Genadek, Ronald Goeken, Josiah Grover, and Matthew Sobek. Integrated Public Use Microdata Series: Version 7.0 [dataset]. Minne- apolis: University of Minnesota, 2017. doi.org/10.18128/D010.V7.0.