Was Ulysses S. Grant's presidency impacted by corruption?

Ulysses S. Grant was the Union's answer to Robert E. Lee, the Confederate general whose tactics and strategy for a time confounded the Union's efforts to defeat the Confederate South. Grant was known as a soldier's soldier. He preferred to spend his time in the field with the men he led as opposed to remaining safe and secure far from enemy lines as many officers did during the battle. Union soldiers were extraordinarily loyal to the personable and relatable Grant. Grant was an outstanding military leader and as a popular hero, he won the election in 1869.
The characteristics that made him a hero in the chaos of battle were of little use to him as a politician. Historians have used terms such as aloof, bewildered, confused, incompetent, or out of place to describe his time in office. The political wrangling of Washington did not fit with the free-willing former general accustomed to making decisions with little input and resistance.
While there is scant evidence to suggest Grant was corrupt, the men he placed in positions of power were notorious for unscrupulous wheeling and dealing. Two men, Jay Gould and James Fisk, were implicated in a scheme to monopolize the gold market which forced Grant's administration to sell gold to hold off a potential economic disaster. Grant's loyalty to friends also created problems for him. Appointing men with little government or business experience to federal offices, many of his appointees participated either through ignorance or intent in several questionable deals that skirted even the loose ethical standards of the government in Grant's day.
An example of the type of scandals that plagued Grant's administration is the Credit Mobilier scandal in 1872. The scandal impacted the primary transportation system of the United States, the railroads. Millions of dollars were paid by the federal government to railroads in overcharges and fraudulent billing. Compounding the inflated charges was the discovery that railroads had paid bribes and kickbacks to government officials associated with the Grant administration in the form of stock and cash.
Another scandal discovered in a Congressional investigation found that federal agents were skimming money from federal excise taxes collected on distillery products. Participants in the scandal became known as the Whiskey Ring and Grant's personal secretary, Orville Babcock, was indicted in the scam. Grant did himself no favors by choosing to testify on behalf of Babcock instead of distancing himself from the scandal. Babcock was found not guilty in the trial, but again the loyalist tendency of Grant made it challenging for him to separate friendship from men who saw an opportunity to capitalize on Grant's refusal to believe any of the men he appointed were nothing less than honorable.
There were several less notable scandals involving various officials appointed by Grant. These scandals were probably no worse than those of his predecessors, but given Grant's propensity to look the other way and the accumulation of the other notable scandals, Grant's administration earned a reputation as corrupt. Ulysses S. Grant was never implicated as a participant in the scandals, and as far as historians can determine, it was his blindfolded sense of loyalty and hands-off management style that resulted in many of the scandals plaguing the Grant administration.
Furthermore, in a somewhat ironic twist, Grant introduced legislation to reform the civil service to reduce the influence of patronage and end some of the ethically questionable practices that were hallmarks of previous administrations. The legislation did not pass until after Grant had left the office.
https://millercenter.org/president/grant/domestic-affairs

https://www.biography.com/us-president/ulysses-s-grant

https://www.whitehouse.gov/about-the-white-house/presidents/ulysses-s-grant/