Final answer:
Dr. Harry Benjamin is renowned for his work in affirmative treatment for transgender individuals in the U.S., establishing the Harry Benjamin Foundation and contributing to the field's development. Reed Erickson, another key figure, supported research and services through the Erickson Educational Foundation and assisted the progress of transgender care standards through his philanthropy.
Step-by-step explanation:
The endocrinologist and sexologist well known for his work in affirmative treatment for trans folks in the U.S. is Dr. Harry Benjamin. Born in Berlin, Germany, in 1885, Dr. Benjamin moved to New York in the 1920s and initiated a practice devoted to endocrinology and gender identity. He became a seminal figure for transgender individuals seeking medical treatment from then until the 1960s, helping notable patients such as Christine Jorgensen, Reed Erickson, and Renée Richards. In the 1960s, he established the Harry Benjamin Foundation, which aided transgender people in obtaining surgery, and in 1966, he published the landmark The Transsexual Phenomenon.
Reed Erickson, a client of Dr. Benjamin, also left a significant mark on the field by founding the Erickson Educational Foundation in 1964, which supported transgender issues through donations and educational efforts. This foundation played a pivotal role in advancing transgender medical and support services during the 1960s and 1970s. Furthermore, the Harry Benjamin International Gender Dysphoria Association (HBIGDA), named in honor of Dr. Benjamin, was established in 1979, providing standardized procedures for reassignment treatments and contributing significantly to transgender advocacy.