The phrase "marched upon" can be replaced with a variety of synonyms to add variety and interest to writing. Some options include: advanced, approached, converged, moved forward, proceeded, progressed, set forth, stepped forward, and trod upon. These alternatives can be used in a range of contexts, from a military takeover to a peaceful protest march. Experimenting with different synonyms can also help to convey different tones or moods, such as urgency, determination, or aggression. Ultimately, the choice of synonym will depend on the specific context and desired effect for the reader.