Mickelson drilled a long birdie on his final hole and Horschel made every green in regulation to be the only two players below par.
The modern-day championship on the historic Merion course faces bad weather as the US Open tees off on Thursday.
There has not been any official word from the Wharton School on withdrawal of sponsors and its impact on the conference.
Here is the full text of the letter which led to Wharton cancelling its invite to Narendra Modi.
The Wharton India Economic Forum revoked its decision on Sunday to invite Gujarat Chief Minister Narendra Modi to deliver a key note address.
Modi was invited by the Forum to deliver the keynote address at its annual conference via video conference.
Investigators suspect shooter might have been driving when he opened fire, firing at people for unknown reasons.
Pennsylvania had been considered to be in Obama's column for much of the campaign.
Hurricane Sandy is moving slowly toward the north-northeast but is expected to turn to the north and west later Sunday and Monday, forecasters say.
Sandy killed more than 40 people in the Caribbean, wrecked homes and knocked down trees and power lines.
A 10-month-old child of Indian origin, baby Saanvi Venna, who was kidnapped four days ago from her home in Pennsylvania, was found murdered in Santiago on Friday.
Surendra Mohapatra, a 1986 batch officer, was arrested in Pennsylvania reportedly on Wednesday.
The couple's family, however, maintains the act was committed out of nothing but 'deep devotion'.
Students from top American universities, including Columbia, Cornell and Harvard, would participate in the fourth edition of the Yale Hindi debate.
Three Indians in collaboration with the University of Pennsylvania have developed a belt that senses obstructions.
Catasauqua Area School District now allows students to wear so-called skinny jeans.
The study focused on the complicated relationship between positive emotions and food consumption.
Most people would be quite comfortable pocketing an extra $ 20, when the cashier is not looking.