Rosevelt's populist agenda called for "vigorous measures to eradicate perceived political corruption" This included that contributions made by corporations for political purposes should be outlawed. The Federal Corrupt Practices Act was later passed, which required House and Senate candidates to disclose their finances.

https://ballotpedia.org/History_of_campaign_finance_regulation

Two and a Half million Union soldiers served during the four year conflict of the civil war. Of that, three hundred and fifty thousand were killed. Nearly 15% of the Union Army would lose their lives, being the largest loss of life for the United States military in any war or conflict to date. The honor and recognition Rosevelt mentions they are owed, was paid in blood. As a combat veteran who has lost multiple friends teammates, I understand the toll that was paid for freedom.

Gilman, J. (1910) The Grand Army of the Republic. www.civilwarhome.com/grandarmyofrepublic.html

The event in Kansas Rosevelt references was know as "Bleeding Kansas". Violence between pro and anti-slavery groups began to erupt throughout the state. The violence boiled over in 1856 when "a mob of more than 800 southerners descended on the town of Lawrence with a blood-red flag...the free-soilers had no protection; the residents fled their homes as the southerners ransacked their town." (Vega, 2021.) Vega, S. (2021) Bleeding Kansas: The Story of John Brown. https://stmuscholars.org/bleeding-kansas-the-story-of-john-brown/