Question

click to correct the pronoun if needed.
abraham lincoln invented an inflatable device for buoying a boat in shallow waters. him and a mechanic named walter davis even went so far as to create a model, but the device was never put into production.

Explanation:

The pronoun "Him" is incorrect. In this context, we need the subject - form of the pronoun. The correct pronoun is "He" because it is the subject of the verb "went".

Answer:

He