Conversation so far:
where did the old spanish trail start and end
In 1829, an intrepid merchant opened a trade route, today known as the Old Spanish Trail, between Los Angeles and Santa Fe.
how long was the old spanish trail
The Old Spanish Trail was approximately 700 mi long
where does the name old spanish trail come from
The Old Spanish Trail name comes from John C. Frémont’s Report of his 1844 journey for the US Topographical Corps, acknowledging that the Spanish knew parts of the trail

Question: what was the purpose of the trail
Self-contained rewrite: what was the purpose of the old spanish trail