Bishop Henry B. Whipple, a native of upstate New York, was an unlikely advocate for Native Americans. A missionary priest in Chicago until he was elected Minnesota's first Episcopal bishop in 1859, he didn't even know a Native American until he was 37 years old.

In Minnesota, however, Whipple not only met Indians he respected, he also saw firsthand how the federal Office of Indian Affairs conducted itself, and he soon concluded that the agency was corrupt and that its agents were mostly political hacks who cared little about those they were supposed to serve. He also came to regard the traders licensed to do business with Indians as a problem: greedy, dealing illegally in liquor and abusive of Indian women. And, as with so many other social reformers through history, Whipple regarded the situation not only as an injustice but as an offense to religious principles that demanded action

In 1860, he began a letter-writing campaign, laying out his concerns and proposing ideas to remedy the problem. He wrote to Episcopalian groups, influential business friends, Minnesota's congressional delegation, to Lincoln's predecessor, President James Buchanan (who never responded), and ultimately to Lincoln himself. Critics called the bishop naive and claimed his interventions on behalf of Native Americans were causing him to neglect his white flock, something he denied.

Early in 1862, he received from Lincoln a courteous reply to one of his letters. The bishop, wanting to press the matter further, traveled to Washington to meet with Lincoln in mid-September 1862, a fraught and momentous time. Confederate Gen. Robert E. Lee had just invaded Maryland and seemed poised to threaten Washington. Lincoln had privately drafted a preliminary Emancipation Proclamation to free the South's slaves, which he would release if Union forces defeated Lee.