Generally speaking, the midpoint is in Colorado, but this depends on the starting cities.
For example, the midpoint between Los Angeles and Milwaukee is along Interstate 76, Commerce City, CO.
See also:http://www.meetways.com for something more specific.
The city that is the halfway point between Wisconsin and Virginia is New Hope, Ohio. It is the exact halfway point.
Eureka Center, Wisconsin is the halfway point.
The halfway point between Wisconsin (WI) and Vermont (VT) is Pepper Pike, Ohio.
The halfway point between Milwaukee, Wisconsin and Toronto, Canada is Lansing, Michigan.
India
Missouri
There is 610 miles between Milwaukee, Wisconsin, and Toronto, Canada. The halfway point between these two cities is Lansing, Michigan.
Acebedo, CA is the halfway point.
North Dakota
Tennessee
That depends greatly on where in Texas and where in Wisconsin. If you go by closest point to closest point, then Missouri is halfway.
The halfway point between St. Paul, Minnesota, and Milwaukee, Wisconsin, is Tomah, Wisconsin, right where I-90 and I-94 merge.