The Humane League

As of February 2015, THL had been involved in at least 67 successful campaigns to convince corporations to use only non-battery cage eggs. These victories include major corporations Costco, Grupo Bimbo, Starbucks, Compass Group, and Dunkin' Donuts. According to the Open Philanthropy Project, "Other leading organizations in corporate campaigns have consistently reported to us that THL plays a key role in these campaigns."[4] In March 2015 THL won a major victory with a cage-free pledge by Sodexo.[7] In 2016 THL continued to secure cage-free commitments from major corporations, including Kroger, Denny's, and Restaurant Brands International (parent company of Burger King). According to THL, cage-free commitments secured in the first quarter of 2016 will affect tens of millions of hens.[8]

Following negotiations with THL, United Egg Producers—which represents companies that produce 95% of all eggs produced in the United States—announced it will eliminate the culling of male chicks by 2020. Chick culling refers to the routine killing of male chicks (which are useless for meat or egg-laying), usually by gassing or grinding them alive. Under this policy, millions fewer chicks will be killed each year.[9]

In December 2018, THL, along with 59 other major animal welfare organizations, secured a cage-free commitment with Marriott International by 2025.[10]

In 2021, THL released a report which found that "99% of U.S. store-brand chickens" were afflicted by white striping,[11] a poultry disease that causes "elevated serum creatine kinase levels, increased fat content in pectoral muscle, gross white striations in the direction of muscle fiber, and hypertrophy of pectoral muscle which are similar to observations in hereditary muscular dystrophy"[12]

Grassroots outreach is a major focus of THL. According to ACE, THL distributed 841,778 leaflets and reached 4,358 students through humane education in the first three quarters of 2015.[13] THL has a Campus Organizer program in which college students are paid a stipend to lead animal activist efforts on their college campus.[14]

Outreach via online ads is another of THL's main activities. The organization reported 1,942,924 clicks on their ads in the first three quarters of 2015.[13]

THL was awarded a $1 million grant by the Open Philanthropy Project (abbreviated Open Phil, and a spinoff of GiveWell working in collaboration with Good Ventures) for its corporate cage-free campaign.[4] The grant was part of a larger strategy by the Open Philanthropy Project to fund corporate cage-free campaigns, with other grant recipients including Mercy for Animals and The Humane Society of the United States.[24]

In July 2016, Open Phil awarded another $1 million to THL for expanding international cage-free advocacy, with a focus on Latin America, Europe, and Japan.[5] The grant was announced along with four other similar grants, totaling about $2.6 million. The other recipient organizations were Mercy for Animals, Humane Society International, Animal Equality, and People for Animals.[25]

In November 2016, Open Phil made a $1 million grant to THL for general support.[4] The grant was announced along with a $1 million grant for general support to Mercy for Animals.[26]

In September 2017, Open Phil made a $2 million grant to THL for general support of the Open Wing Alliance.[27] It was followed up by a $1.5 million grant to the same organization in March 2019.