For years my favorite chart of the USA has been the 7 Gemini 35 rising chart, which was taught by Elbert Benjamine in his Brotherhood of Light mundane astrology classes. Benjamine said that he was given the 7 Gemini 35 chart by Dr. James D. Keifer in 1908, and Dr. Keifer appears to have originated this chart. Whether Keifer derived this Gemini rising chart from other sources is not known.
In mundane astrology the charts of the equinoxes and solstices are quite significant. Because China reported the early cases of unusual pneumonia to the rest of the world at the end of December 2019, I thought it would be useful to compare the USA Declaration of Independence chart (July 6, 1776) with the Winter Solstice chart of December 21, 2019, which occurred very close to the beginning of the current worldwide pandemic. I set both charts for Philadelphia, which has cusps very close to those of charts set for Washington, DC.
What is striking about these superimposed charts is that natal USA Neptune almost exactly conjoins the 2019 winter solstice Ascendant, and natal USA Mars almost exactly conjoins the 2019 winter solstice Midheaven. Mars, which rejoices in the 6th house, is a general signifier of infections, inflammation and disease. Neptune is a modern symbol of mysterious and hard-to-diagnose illnesses. As the two most angular planets, they set the tone for the months ahead.
Furthermore, Mercury rules the Ascendants of both the natal USA chart and the 2019 winter solstice chart in Philadelphia. As ruler of the Ascendant, Mercury represents the life force, health and vitality of the nation. In the superimposed charts transiting Pluto opposes natal USA Mercury, and natal USA Mars opposes transiting (solstice) Mercury. Thus, Mercury, both natal and transiting, is highly afflicted by malefic planets associated with disease and death. In addition, the most angular aspect is the opposition of solstice Mercury (which rules both Ascendants) and USA natal Mars (which rules the 6th whole sign of the Gemini rising chart).