How many United States presidents served in the American Civil War?
7
2
2
2
2
2
2
1
2
1
2
3
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
5
1
2
3
4
5
1
2
3
4
5
1
3
4
5
1
3
4
5
1
3
0
4
5
1
3
4
5
0
1
3
4
5
1
0
6
3
4
5
6
3
0
7
4
5
6
7
4
5
0
6
7
5
0
6
7
5
6
0
7
5
6
7
5
8
0
6
7
5
8
6
7
5
8
6
7
5
8
9
6
7
5
8
9
6
7
5
8
9
13
6
11
7
8
9
13
6
11
7
8
10
9
13
6
11
7
8
10
9
13
6
11
7
8
10
9
13
6
11
7
8
10
9
13
6
11
7
12
8
10
9
No
13
6
11
7
12
8
10
9
No
13
6
11
7
12
8
No
265