Problem importing/opening multiple audio files


I have about a dozen mp3 audio files of various lengths in a folder. Total duration is 1h15m.
I want to put all of these sequentially into a single long mp3 file.
I’ve tried the following:

  1. Open audacity
  2. File>Import>Audio…(directs to folder containing target files)
  3. Selected all files (by highlighting all)
  4. Click Open
    Audacity will import all the files in sequence up to about 7 minutes total duration on the timeline.
    Then, after a hiccup (importing continues but total duration of timeline actually drops down to under 5 minutes) total duration on timeline increases to about 10 minutes total duration.
    Then importing continues but timeline shrinks back to under 5 minutes, then increases to 16m and then up and down. At the end, my 1h 15m of music occupies under 14 minutes.
    If I play back, it’s evident that various mp3 files have been imported on top of each other instead of sequentially, so I have a jumble of sound. (Surrealistic, but not what I’m looking for.)
    What is the fix for this??
    Thanks in advance for any help.

Sorry, forgot to include this:
I’m running Win7, 64bit, and Audacity 2.1.1.

Once all the files have been imported, select all tracks, then use align end to end for “sequentially”.

Thanks! I had done this type of thing before but it has been a couple of years and I forgot about the last step.