In 1865, he accompanied future Vice President of the United States Schuyler Colfax on a trip west to California, later publishing a book about the excursion.

The paper espoused Democratic viewpoints, but differed from the party line regarding slavery, notably opposing Stephen A. Douglas's Missouri Compromise.

He gave the first public endorsement of John C. Frémont for President in the West, speaking at Dearborn Park the night he was nominated.

[2] While at the former State House in Vandalia, Illinois, he became acquainted with fellow Frémont campaigner Abraham Lincoln and the two would often speak at the same engagements.

[2] Bross's support of Lincoln helped him to gain nomination as the Republican candidate for Lieutenant Governor of Illinois under Richard J. Oglesby.

He traveled with Speaker of the United States House of Representatives Schuyler Colfax in 1865 to examine the path west to California.

He donated $40,000 to invest over ten years to buy literature "on the connection, relation, and mutual bearing of any practical science, the history of our race, or the facts in any department of knowledge, with and upon the Christian Religion."

University trustees offered $6,000 as a prize to one who would author a book best fulfilling these conditions; it was won by James Orr of United Free Church College for Problems of the Old Testament Considered with Reference to Recent Criticism.

The fund also enabled the university to pay for lecturers, who included Francis Landey Patton, Marcus Dods, John Arthur Thomson, Frederick J. Bliss, and Josiah Royce.