Roman Klen b. 1816 in Baden
Madlenea Klen b. 1819 in France
John Klen b. 1851 in Ohio
Elizabeth Klen b. 1854 in Ohio
Loudweek (Ludwig?) Klen b. 1855 in Ohio
The 1870 census has...
Roman Klem b. 1816 Baden
Elizabeth Klem b. 1828 Hanover (step mother)
Elizabeth Klem b. 1854 Ohio
Louis Klem b. 1856 Ohio
No way was he 30 inches tall when he as in the Army.
According to his photograph taken in 1863, using his regulation 1851 eagle belt buckle as a guide (just over 2 inches in width), he had to be at least 40 inches in height. Standard snare drum for infantry was 14-16 inches in height. Civil War drummers carried their drums low, right at crotch level, in order to get the full use of their arms without holding them up for long periods. Also the drums were held at an angle of about 45 degrees, plus the OD was usually wider than the height, making height closer to 20-25 inches when marching. Little Johnny Clem would be tripping all over that drum in the field.
The first photo on the web site below looks like they tried to make him look shorter than he was. The photo with him holding what looks to be an 1858 Enfield Rifle, regulation length of 55 inches. Using the Enfield as a measuring tool, and taking into account he is holding it at rest, he seems to be at least just over 47 inches in height. Using the picture of the John L. Clem's statue in Newark, Ohio, if the drum is regulation, he would be about 5 1/2 feet tall.