Is it legal to fire someone and subsequently hire someone else for virtually the same position without first offering it to the the employ who was terminated?

Unfortunately, it is legal. Companies may (in the absence of a contract to the contrary) fire employees at will, for any reason. They also have complete discretion in hiring. Therefore, they could fire, or lay off, person A and then hire person B for the same, or closely similar, job/title and it is perfectly legal. There is no bar to hiring someone for a position similar to one from which a person was recently terminated.

There is no requirement to offer an ex-employee back before hiring someone else for essentially doing the same job. .Most employment relationships are what is known as "at will".  This means that you can work for an employer, or not, your choice.  In turn, the employer can hire or fire someone for any reason or no reason whatsoever.

The only exceptions to this are: 1) If there is an employment agreement or contract (which governs termination); 2) If there is a union or collective bargaining agreement (which governs termination); 3) If there is an employee handbook or other official policy statement (which governs termination); 4) If discrimination is a factor (there can be no termination for reasons of race, religion, age, disability, sex, national origin).