Sherman, Texas is a great place to stop/stay in between trip to San Antonio and Springfield, MO. It is approx. 300 miles from San Antonio and about 340 from Springfield.
Not quite the midway point, but Tulsa, Oklahoma is about the midway point between the two.
Sherman Texas
The halfway point between Monticello, IA and Springfield, MO falls in or around Perry, Missouri.
The half way point between Mount Vernon Texas and Springfield Missouri would be Little Rock Arkansas. This would be in the middle.
The halfway point between St. Louis, Missouri, and Norfolk, Virginia is in or around Elementary Drive, Ona, West Virginia, 25545. Huntington lies halfway between St Louis MO and Norfolk VA
no
Assuming you're taking I-44, the halfway point is near Plano, Missouri but locations in the west part of Springfield are close enough.
The halfway point between Lafayette, Georgia and Clinton, Missouri, falls in Charleston, Missouri.
The halfway point between Mt. Pleasant, Iowa, and Branson, Missouri, is about halfway between Fulton and Jefferson City, Missouri.
Springfield
Grand Island, Nebraska
Sterling, CO
a few miles northwest of Chicago
my house