More than 3.8GW in 29 states began construction or advanced development during the quarter, bringing the total to 25.8GW under way.
Nearly 80% of that is the Midwest, Texas and the Mountain West, according to the latest data from the American Wind Energy Association (AWEA).
Six major commercial and industrial customers bought US wind power for the first time, including food giant General Mills.
Other first-time power purchasers during the quarter included Apple, T-Mobile, Goldman Sachs, Akamai Technologies and Partners Healthcare.
Kansas became the fifth state to pass 5GW of installed capacity, said AWEA.
Kansas Governor Sam Brownback said: "Here's to the next 5GW of wind energy capacity in Kansas and the jobs, businesses and private capital it brings."
The US now has 84,405MW of installed wind power capacity.