Just read the following on Wikipedia.
In the 19th century, the power of the preceding House Clerk to organize the House played a significant role at the beginning of several congresses...at the first meeting of the 26th Congress...House Clerk Hugh Garland omitted the names of five Whigs from New Jersey from the roll call...the Whigs were not seated, effectively creating a Democratic majority in a closely divided House. Only then was the roll call completed and a Speaker elected