173 US-Businesses (including Apple, Nike, Ikea, Target) signed a letter urging senators to pass the Respect for Marriage Act. This would nationally codify federal marriage equality by guaranteeing the federal rights, benefits, and obligations of marriages in the federal code. 
“Together we, the signatories of this letter, write in support of the Respect for Marriage Act (H.R. 8404/S. 4556) representing a diversity of industries and brands that do business, serve customers and create jobs in nearly every community in the United States. Fairness, equal treatment, and opportunity are central to our corporate values because we care about our employees and the customers we serve. […]”

More information can be found here.