Circumcision… Why the controversy?
Circumcision was common but not all encompassing among ancient Semitic peoples. The reasons for it are not known with solidity. Many think it began as a religious rite or rite of passage for boys into adulthood. In ancient times it was also thought to aid cleanliness.
The first medical doctor to advocate its adoption in the English-speaking world was Jonathan Hutchinson. 
Although his studies have since been proven flawed, he claimed that circumcised men were less vulnerable to STD’s like syphilis.
In a British Medical journal he asserted that the foreskin was a haven for filth and a constant source of irritation. He added that it promoted masturbation, a great concern of his time. Other doctors added that circumcision acted as an effective measure against the prevention of some cases of epilepsy and chorea.
As these beliefs became common they were applied to females as well. One Baker Brown
, an obstetrical surgeon, recommended the use of clitoridectomy as a cure for several conditions. This procedure involved the removal of the clitoris. He claimed that such diseases as epilepsy, catalepsy, and mania, which he attributed to masturbation, would be cured. He was eventually expelled from the Obstetrical Society of London for carrying out these operations without the knowledge or permission of the patient.
An interesting article is available for your perusal on Wikipedia : Male Circumcision.
Opinion:
I consider circumcision an unnecessary and barbaric holdover from a time of ignorance. Though not conclusive, some studies have pointed to the possibility of trauma to the infant male. Female circumcision has been made illegal in the United States. It is time to make male circumcision illegal here as well.
Freethinker's corner 
Beware of Wikipedia as a source on circumcision. For a long time an avid advocate ruthlessly censored all information against male genital cutting.
Whether it causes trauma in babies, many men hate that it was done to them, and if we don’t listen to them, who do we listen to? It is NOT like other “parental choices” – to cut a normal, healthy, functional, non-renewing part off a person’s genitals is uniquely invasive. We recognise this when the people are female (no matter how little is removed). Equality demands no less for males.
Presently in the United States the practice of circumcision is reserved for males only. The procedure occurs at a time in the life of the child when no personal decision is possible.
It has been conjectured that long lasting trauma, not readily visible, may lead to the child becoming violent upon maturity. I agree, males should have this right to have intact genitals, and be able to make their own decisions later in life.