In the 1840s the main argument in Congress over the transcontinental railroad concerned?

In the 1840s, the main argument in Congress over the transcontinental railroad centered on the routes and the political implications of its construction. Disputes arose primarily between Northern and Southern lawmakers regarding whether the railroad should run through free states or slave states, reflecting broader sectional tensions. Additionally, issues of federal land grants and funding for the project were contentious topics, as different regions sought to secure economic benefits from the railroad's construction. This debate foreshadowed the growing divide between North and South leading up to the Civil War.