To find the slope of line \( d \) that passes through the points \((48, 87)\) and \((49, 88)\), we can use the slope formula:
\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Here, let \((x_1, y_1) = (48, 87)\) and \((x_2, y_2) = (49, 88)\). Plugging in these values, we have:
\[ m = \frac{88 - 87}{49 - 48} = \frac{1}{1} = 1 \]
Thus, the slope of line \( d \) is \( 1 \).
Because line \( e \) is parallel to line \( d \), it will have the same slope. Therefore, the slope of line \( e \) is also:
\[ \boxed{1} \]