Step-by-step explanation:
This process seemed to work well until the mid-1850s. At that time, growing hostilities in various states resulted in vacant Senate seats. In Indiana, for example, the conflict between Democrats in the southern half of the state and the emerging Republican Party in the northern half prevented the election of any candidate, thereby leaving the Senate seat vacant for two years. This marked the beginning of many contentious battles in state legislatures, as the struggle to elect senators reflected the increasing tensions over slavery and states' rights that led to the Civil War.
After the Civil War, problems in senatorial elections by the state legislatures multiplied. In one case in the late 1860s, the election of Senator John Stockton of New Jersey was contested on the grounds that he had been elected by a plurality rather than a majority in the state legislature.