Unfortunately, many of these wonderful animals die because of poor care. Please do not take box turtles from the wild. Their numbers are dwindling because of habitat loss and pressure from the pet trade. Pet stores sell wild caught turtles almost exclusively, so these should also be avoided. Or check with local rescue organizations for turtles needing homes.
Box turtles tend to do well either outdoors, or in a large indoor enclosure.
Many people do keep them in tiny aquariums, but it is a rather sad existence, in my opinion. One type of indoor container that actually works quite well is a large Rubbermaid tub. Rubbermaid tubs and specially built wooden boxes have an advantage over glass aquariums because they have opaque sides. Some box turtles will obsessively try to get through the glass to get to the larger area that they can see on the other side. Others become frightened by any activity in the room and will not relax until the sides are covered.