If DTaP #4 is given with at least a 4-month interval after DTaP #3, it does not need to be repeated. The minimum age of 12 months for the fourth dose must be met. Decreasing the interval to less than 6 months, however, is not recommended.
The total given by the VA for the Indian Wars (1,000) seems to be a wild guess. Just two major defeats -- Custer's and St. Clair's -- add up to about 900 dead all by themselves. The official number of Americans killed in the Revolutionary War (4,435) is only about 2/3 the numbers usually given by historians. The total of US combat deaths during the Civil War is given as 140,414 -- or some 30,000 higher than most historians would estimate. I suspect (but don't know for sure) that the boost may come from the DoD counting deaths among POWs as combat rather than disease.
While the Union lost about 1,500 killed and wounded, the Confederate casualty rate was over 50%. Pickett's division suffered 2,655 casualties (498 killed, 643 wounded, 833 wounded and captured, and 681 captured, unwounded). Pettigrew's losses are estimated to be about 2,700 (470 killed, 1,893 wounded, 337 captured).