According to flight tracking program, FlightAware, Flight 1549, enroute from LaGuardia to Charlotte, took off at approximately 1526h and climbed as high as 3,200ft before beginning a descent.
The final radar data from the tracking program indicates the aircraft travelling at 153kt at 300ft altitude at 1531h.
The US FAA says there were 148 passengers onboard and five crew, and that it appeared that everyone had been evacuated. There are indications that the aircraft may have struck a flock of birds, also according to the FAA. According to CNN, three minutes after takeoff, the pilot radioed controllers that he had sustained a "double hit" and had to return for an emergency landing.
The graphic below shows data from FlightAware from takeoff (bottom rigth) to final data point (bottom left). Data next to each point shows time (military), airspeed and altitude, along with latitude and longitude.
Source: Air Transport Intelligence news