Apple, Inc. employees pass out free iTunes song cards at San Francisco LGBT Pride Parade

The LGBT Pride event is an annual celebration held in support of civil rights and a reminder of the violence, discrimination and social stigma that were once pervasive against minorities of gender identity and sexual preference— as well as a reminder of further work that needs to be done.

San Francisco's annual Pride event is held throughout June, culminating in a series of celebrations and events during the last week of the month, including the parade. Employees posted photos from the event, including more than a few selfies with Cook. Cook posted his own tweet, stating "Congrats to 5000 Apple employees/families who attended today's Pride parade. Inclusion inspires innovation."

Jackson, who joined the company last year from the U.S. Environmental Protection Agency, posted a photo noting she was "honored to be a banner carrier," and portraying the company's iconic logo drawn in the rainbow colors associated with Pride diversity above simply, "Pride."

The LGBT Pride parade serves in part as a reminder of the June 1969 Stonewall Riots, a significant event in America's history of routine oppression and violent arrests of gays when patrons at New York City's Stonewall Inn gay bar fought back after a police raid, furthering the emerging new era of civil rights protests and budding political representation of LGBT minorities.

Cook has repeatedly addressed civil rights as an important issue, and Apple has frequently contributed to efforts seeking to end discrimination and to call attention to human rights issues, including those affecting lesbians, gays and transgendered people.

In April 2011, Apple employees contributed a "It Gets Better" video to the Trevor Project— an effort to support youth contemplating suicide— offering positive messages of encouragement voiced by adults who have lived through the same kind of stigma and bullying.

Apple has not sponsored an officially sanctioned group marching in the San Francisco parade before. David James, one of the participants of the "It Gets Better" video, was at the parade today, noting via Instagram "Let's make history today! But first let me take a #selfie," posting a photo he took with Cook.